Added save and load user data to CarVolumeGroup

Added save and load user data for CarVolumeGroup gain index. This allows
for users to load their previously set volume preferences when the user
is switched. Added test for added logic to CarVolumeGroupTest.

Bug: 136353051
Test: atest CarVolumeGroupTest
Change-Id: Idb04ef8925e4324312726a07e100090502365a37
7 files changed
tree: 8494b4447fca527b402c3f82fdc13ce4bfe30199
  1. car-bugreportd/
  2. car-default-input-service/
  3. car-lib/
  4. car-maps-placeholder/
  5. car-systemtest-lib/
  6. car-test-lib/
  7. car-usb-handler/
  8. car_product/
  9. EncryptionRunner/
  10. evs/
  11. FrameworkPackageStubs/
  12. media-router/
  13. obd2-lib/
  14. procfs-inspector/
  15. service/
  16. tests/
  17. tools/
  18. user/
  19. vehicle-hal-support-lib/
  20. .clang-format
  21. .gitignore
  22. Android.mk
  23. CleanSpec.mk
  24. OWNERS
  25. PREUPLOAD.cfg
  26. README.md
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.