Changes to make diff in AndroidEnvironment smaller

src/Mono.Android/Android.Runtime/AndroidEnvironment.cs

@@ -363,21 +363,27 @@ static Type TypeGetType (string typeName) =>
 
 		static bool IsAcceptableHttpMessageHandlerType (Type handlerType)
 		{
-			if (Type.GetType ("System.Net.Http.HttpClientHandler, System.Net.Http", throwOnError: false) is Type httpClientHandlerType &&
-				httpClientHandlerType.IsAssignableFrom (handlerType)) {
+			if (Extends (handlerType, "System.Net.Http.HttpClientHandler, System.Net.Http")) {
 				// It's not possible to construct HttpClientHandler in this method because it would cause infinite recursion
 				// as HttpClientHandler's constructor calls the GetHttpMessageHandler function
 				Logger.Log (LogLevel.Warn, "MonoAndroid", $"The type {handlerType.AssemblyQualifiedName} cannot be used as the native HTTP handler because it is derived from System.Net.Htt.HttpClientHandler. Use a type that extends System.Net.Http.HttpMessageHandler instead.");
 				return false;
 			}
-			if (Type.GetType ("System.Net.Http.HttpMessageHandler, System.Net.Http", throwOnError: false) is Type httpMessageHandlerType &&
-				httpMessageHandlerType.IsAssignableFrom (handlerType)) {
-				return true;
+			if (!Extends (handlerType, "System.Net.Http.HttpMessageHandler, System.Net.Http")) {
+				Logger.Log (LogLevel.Warn, "MonoAndroid", $"The type {handlerType.AssemblyQualifiedName} set as the default HTTP handler is invalid. Use a type that extends System.Net.Http.HttpMessageHandler.");
+				return false;
 			}
 
-			// Was not an acceptable type
-			Logger.Log (LogLevel.Warn, "MonoAndroid", $"The type {handlerType.AssemblyQualifiedName} set as the default HTTP handler is invalid. Use a type that extends System.Net.Http.HttpMessageHandler.");
-			return false;
+			return true;
+		}
+
+		static bool Extends (
+				Type handlerType,
+				[DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)]
+				string baseTypeName)
+		{
+			var baseType = Type.GetType (baseTypeName, throwOnError: false);
+			return baseType?.IsAssignableFrom (handlerType) ?? false;
 		}
 
 		[return: DynamicallyAccessedMembers (DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)]