aaudio: enable exclusive MMAP mode support

Allow exclusive MMAP mode only if the HAL indicates
that the FD returned for shared memory buffer can be shared
with any application.

NOTE: the way the HAL indicates this is temporary until the audio
HAL is modified in next HIDL release.

Bug: 37167970
Test: check playback and capture in mmap exclusive and shared mode
Change-Id: I09c1461b2f99532ded2ef9d36d483b82096fda68
6 files changed