btaa: introduce activity attribution JNI /jni implmentation

Introduce the /jni cpp portion of the new Activity Attribution (BTAA)
JNI interface.

Tag: #feature
Bug: 172501038
Test: atest BluetoothInstrumentationTests:com.android.bluetooth.\
btservice.activityattribution

Change-Id: I4680e2195a5d016a2250825ea98632ede79aedbf