fix(dynamic-links): ios parameters builder assigned to wrong variable

[mukaschultze]

Fix the variable assignment for DynamicLinkIOSParameters on Android, it's currently assigning the builder to the native parameters object. This incorrect assignment causes the following error when trying to generate short links:

JNI DETECTED ERROR IN APPLICATION: bad arguments passed to com.google.firebase.dynamiclinks.DynamicLink$Builder com.google.firebase.dynamiclinks.DynamicLink$Builder.setIosParameters(com.google.firebase.dynamiclinks.DynamicLink$IosParameters) (see above for details)