The following HAL methods use file descriptors to write dump
info comprising audioflinger debug dump:

IDevice.debugDump
IEffectsFactory.debugDump
IStream.debugDump

Bug: 37993476
Test: check contents of media.audio_flinger section in
      a bugreport captured on Pixel device
Merged-In: I77d347c019ac93c3ba0d54ce50f0fdc243b04685

Change-Id: Ia0531f715ae5f8b2599153e54a11e9eb4ee47d4b