Invalid Android minimal SDK version

[MGlolenstine]

In the README, there's a specified minimal SDK version of 21, but there's a method called, which was added in SDK 26.

There's an issue that's related to this, and another one mentioning it.

Ideas for solutions:

• Revert jackson to 2.13.x
  • this probably won't return the SDK 21 compatibility, as it would seem like it should support SDK 24 onwards.
• Change the minimal requirements in the README.

Crash log

E/AndroidRuntime( 7561): FATAL EXCEPTION: main
E/AndroidRuntime( 7561): Process: update.test.nordic_dfu, PID: 7561
E/AndroidRuntime( 7561): java.lang.NoSuchMethodError: No virtual method getParameterCount()I in class Ljava/lang/reflect/Method; or its super classes (declaration of 'java.lang.reflect.Method' appears in /system/framework/core-oj.jar)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.AnnotatedMethodCollector._isIncludableMemberMethod(AnnotatedMethodCollector.java:187)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.AnnotatedMethodCollector._addMemberMethods(AnnotatedMethodCollector.java:118)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.AnnotatedMethodCollector.collect(AnnotatedMethodCollector.java:54)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.AnnotatedMethodCollector.collectMethods(AnnotatedMethodCollector.java:40)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.AnnotatedClass._methods(AnnotatedClass.java:387)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.AnnotatedClass.memberMethods(AnnotatedClass.java:327)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector._addMethods(POJOPropertiesCollector.java:685)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.collectAll(POJOPropertiesCollector.java:427)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.getPropertyMap(POJOPropertiesCollector.java:391)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.getProperties(POJOPropertiesCollector.java:233)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.BasicBeanDescription._properties(BasicBeanDescription.java:164)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.introspect.BasicBeanDescription.findProperties(BasicBeanDescription.java:239)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory._findCreatorsFromProperties(BasicDeserializerFactory.java:328)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory._constructDefaultValueInstantiator(BasicDeserializerFactory.java:272)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.findValueInstantiator(BasicDeserializerFactory.java:223)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.buildBeanDeserializer(BeanDeserializerFactory.java:262)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.createBeanDeserializer(BeanDeserializerFactory.java:151)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer2(DeserializerCache.java:415)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:350)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:264)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:142)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.DeserializationContext.findRootValueDeserializer(DeserializationContext.java:648)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.ObjectMapper._findRootDeserializer(ObjectMapper.java:4861)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4731)
E/AndroidRuntime( 7561):        at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3738)
E/AndroidRuntime( 7561):        at io.runtime.mcumgr.util.CBOR.toObject(CBOR.java:31)
E/AndroidRuntime( 7561):        at io.runtime.mcumgr.response.McuMgrResponse.buildResponse(McuMgrResponse.java:247)
E/AndroidRuntime( 7561):        at io.runtime.mcumgr.ble.McuMgrBleTransport$2.onResponse(McuMgrBleTransport.java:409)
E/AndroidRuntime( 7561):        at io.runtime.mcumgr.ble.callback.SmpProtocolSessionKt.onResponse$lambda$1(SmpProtocolSession.kt:156)
E/AndroidRuntime( 7561):        at io.runtime.mcumgr.ble.callback.SmpProtocolSessionKt.$r8$lambda$y5OWzRv1IbLlvC7QCOqni68WVyI(SmpProtocolSession.kt)
E/AndroidRuntime( 7561):        at io.runtime.mcumgr.ble.callback.SmpProtocolSessionKt$$ExternalSyntheticLambda2.run(D8$$SyntheticClass)
E/AndroidRuntime( 7561):        at android.os.Handler.handleCallback(Handler.java:761)
E/AndroidRuntime( 7561):        at android.os.Handler.dispatchMessage(Handler.java:98)
E/AndroidRuntime( 7561):        at android.os.Looper.loop(Looper.java:156)
E/AndroidRuntime( 7561):        at android.app.ActivityThread.main(ActivityThread.java:6523)
E/AndroidRuntime( 7561):        at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime( 7561):        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:942)
E/AndroidRuntime( 7561):        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:832)
I/Process ( 7561): Sending signal. PID: 7561 SIG: 9

For now, I've locked my application to support >= SDK 26, but that differs from the README and locks my application above 8.0, even though this dependency is said to allow lower versions as well.

EDIT: more information about the versioning.
EDIT n2: This PR changed the requirement for the Android SDK version (jackson-core 2.13.3 -> 2.14.2).