hal: Configure frame size of AAC encoded output

BT sink devices have a limitation on the packet sizes
they can receive and handle from BT sources. AAC encoder
can produce output frames which can vary in size based on
content being encoded. If frame size exceeds MTU size of
BT sink device, it will lead to incorrect decoding of
frames in BT sink.
Solve this problem by sending a frame configuration parameter
(MTU/Peak bitrate) while starting A2DP playback on AAC.
Parameter is passed by bthost_ipc to audio HAL which passes
it to DSP during AAC encoder configuration.

Bug: 78907438
Test: Manual testing with AAC headset
Change-Id: I58e30e7e0a486065a95bc7d7463c45e1c5c3e6eb