thread/service/proguard.flags - platform/packages/modules/Connectivity - Git at Google

 # Ensure the callback methods are not stripped
 -keepclassmembers class **.ThreadNetworkControllerService$ThreadNetworkCallback {
     *;
 }
	# Ensure the callback methods are not stripped
	-keepclassmembers class **.ThreadNetworkControllerService$ThreadNetworkCallback {
	*;
	}