Task: Common HAL - Review

[Ulrond]

Subject

• Remove common if possible

• AVSource.aidl -> Should be converted to strings, and removed everywhere. knock on effect to all users.

• HALError.aidl -> Each module should have their own requirements.

• State.aidl -> Each module should have their own version.

Notes (Optional)

• Possible to dissolve away and just replicate inside each HAL that uses them.
• Would reduce cross-deps between HALs.
• Need to break this down into various subtasks, so that each problem can be tackled independently.