Change AUDIO_DEVICE_{IN|OUT}_STUB to enum

These used to be preprocessor defines. As a result
there were creating conflicts when applied to auto generated enums
in other modules.

Bug: 142480271
Test: m
Change-Id: If561bc3a37d2548fb28ae3b9e9424c637a0bb0d2
Merged-In: If561bc3a37d2548fb28ae3b9e9424c637a0bb0d2
1 file changed