Tuner APIs: add locks to runnables to avoid crashes caused by NPE

The executor can be run in a different thread, which can cause race
condition. Adding the lock can help avoid the NPE reported.

Bug: 193604292
Test: atest android.media.tv.tuner.cts.TunerTest
Change-Id: I647ea2b428c1510b1df7f6cecc686bb7eb288a18
5 files changed