Added car playback timeout

If audio plyback stops for a context, a timer will start for that
context and it will remain active until the timeout. During this period
the automatic volume control can still consider the context as active
for volume changes.

Bug: 173141906
Test: atest CarAudioPlaybackCallbackTest
Test: atest CarAudioZoneTest
Change-Id: I43dfd2435102082b248326f3752d7316523cea3c
8 files changed
tree: b75b78556a14e3d7a01ffef5662361df7b8ecd3a
  1. car-admin-ui-lib/
  2. car-bugreportd/
  3. car-internal-lib/
  4. car-lib/
  5. car-maps-placeholder/
  6. car-systemtest-lib/
  7. car-test-lib/
  8. car-usb-handler/
  9. car_product/
  10. cpp/
  11. experimental/
  12. FrameworkPackageStubs/
  13. obd2-lib/
  14. packages/
  15. procfs-inspector/
  16. service/
  17. tests/
  18. tools/
  19. user/
  20. vehicle-hal-support-lib/
  21. .clang-format
  22. .gitignore
  23. Android.mk
  24. CleanSpec.mk
  25. CPPLINT.cfg
  26. OWNERS
  27. PREUPLOAD.cfg
  28. README.md
  29. TEST_MAPPING
README.md

Native (C++) code format is required to be compatible with .clang-format file. Run

git clang-format --style=file --extension='h,cpp,cc' HEAD~

Note that clang-format is not desirable for Android java files. Therefore the command line above is limited to specific extensions.