Merge changes from topic "cherrypicker-L47600000963081744:N22400001405878786" into udc-qpr-dev

* changes:
  audio: Improve testing of point-to-point connections
  audio: Mitigate double receiving of the "exit" command
  Audio : Add 3 VTS test cases for remote submix module
  r_submix : Fix minor issues in AIDL implementation
  Avoid sub_overflow_minimal in AIDL effects VTS
  audio: Properly support external device port with static configs
  Remove unused file EffectWorker.h
  Remove the limitation of max open streams
  audio: Make IConfig.getSurroundSound default implementation more robust