Added API to query active car volume group

Added system API to query active car volume group in a particular zone.
Also added unit tests for internal logic. Also fixed car volume tests
issues related to logic from previous versions. Added car audio
permission test to new car API.

Bug: 173141906
Test: atest com.android.car.audio
Change-Id: Ieda14db9e8b6b7c1b89f857f2f57bd3286fddbfc
7 files changed
tree: 353e046a704bb3b63d2240819504541d3ab3f304
  1. car-bugreportd/
  2. car-internal-lib/
  3. car-lib/
  4. car-maps-placeholder/
  5. car-systemtest-lib/
  6. car-test-lib/
  7. car-usb-handler/
  8. car_product/
  9. cpp/
  10. evs/
  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.