This CL introduces common functions for adding and releasing
native references to reduce the number of JNI functions.
BUG=webrtc:8043
Review-Url: https://codereview.webrtc.org/3003213002
Cr-Commit-Position: refs/heads/master@{#19547}
I decided to make one webrtc/sdk/android/BUILD.gn for both tests and Java/jni src.
External dependencies needs to be updated after this CL.
Future work is required to clean up the Android api and move
implementation details to /webrtc/sdk/android/src.
BUG=webrtc:5882,webrtc:6804
NOPRESUBMIT=True
Review-Url: https://codereview.webrtc.org/2547483003
Cr-Commit-Position: refs/heads/master@{#15443}
