…sink

Refer to original PR: #11549

Update accumulated_written_frames, last_playback_head_position, and
playback_head_position to use 64-bit integers in AudioTrackAudioSink.
At a 48kHz sampling rate, 32-bit signed integers overflow after
approximately 12.4 hours of continuous playback, which can cause
incorrect playback head reporting and audio sync issues.

Also update GetFramesDurationUs to accept int64_t to maintain type
consistency and prevent narrowing.

Note that this doesn't resolve all integer size issues across the audio
pipeline as the Java AudioTrackBridge is still tracking the playback
position using 32 bits integer, which will be resolve in b/539224216.

Bug: 539224216

(cherry picked from commit 97d9944)

Refer to original PR: #11550

Add support for a page alignment flag in DecoderBufferAllocator to
control OS block allocation alignment. This allows for more granular
memory management when using the configurable decommit strategy.

Implement a lockless optimization during suspend by checking an atomic
flag before acquiring the allocator mutex. This prevents unnecessary
blocking of the UI thread when decommit on suspend is not enabled.

Additionally, simplify pointer arithmetic in StarboardMemoryAllocator
using uint8_t pointers and update H5vcc settings to expose the new
alignment configuration bit.

Bug: 454441375

(cherry picked from commit 8ac74bd)