libaudiohal: Implement basic stream I/O

Implement completely DeviceHalAidl::open{Input|Output}Stream.
Implement reading, writing, and position reporting in StreamHalAidl.
Implement pause, resume, and drain for StreamOutHalAidl.

Bug: 205884982
Test: boot cuttlefish with AIDL enabled
Test: run tests from libaudioclient/TEST_MAPPING
Test: atest CtsMediaAudioTestCases
Change-Id: I928593094e4d8adbdecfd22cb3acdd60027924da
Merged-In: I928593094e4d8adbdecfd22cb3acdd60027924da