Implement HCI_Read_Automatic_Flush_Timeout mechanism

Also, read the Automatic Flush Timeout when flushing the A2DP Tx queue

Test: Streaming A2DP headset and trigger audio stutter
Bug: 64038257
Change-Id: Ic49b5236328ddacde1d7f2aee131e35e317a14ef
(cherry picked from commit 2cba2968)