Implement client code to use Drm and Crypto HALs

This change adds DrmHal & CryptoHal classes that connect to the Treble
HAL interfaces for drm.  These classes mirror the existing Drm and
Crypto classes that connect to the DrmPlugin and CryptoPlugin
interfaces. Having both allows mediadrmserver to run in either mode
while the HAL is stabilized.

The shared memory interfaces between mediaserver's ACodecBufferChannel
and ICrypto had to be reworked to use the Treble HALs. Specifically,
the shared memory path for returning decrypted buffers in the
non-secure case had to become separate instead of piggy-backing on the
source shared memory buffer. A separate shared memory destination
buffer is now allocated on the buffer channel. An abstraction for a
decrypt destination buffer was also introduced to clarify ICrypto's
decrypt method.

Tests: Playback using Play Movies and ExoPlayer works on angler
with and without the treble hal enabled.

bug: 32815560
Change-Id: I5a3dc84f99902eb8cf8eabab9ad074d307744950