This CL adds:
1) Setter and getter in DPM to manipulate logging switch (retrieval
method to come in a subsequent CL(s)).
2) A way for DPM to register to listen for events.
3) Skeleton of NetworkLogger class (more to come in subsequent CL(s)).
Bug: 29748723
Change-Id: I5c04662ccc6febd2ba294b0eaca1ed1da9c16e47
This will give us a good place to put all the networking tests.
Fix: 31479480
Test: adb shell am instrument -w -e notClass com.android.server.connectivity.tethering.TetherInterfaceStateMachineTest 'com.android.frameworks.tests.net/android.support.test.runner.AndroidJUnitRunner' # PASS
Change-Id: I4b389f7f4e33a996885b38670f585e58ca66f777