audio HAL: improve control socket error handling

Implement retry upon control socket receive error
in a2dp_ctrl_receive() if EAGAIN or EINTR.

Implement recovery from previous socket error in
a2dp_command().

Increase socket receive timeout to account for
headsets will long activation time.

Fixed state update error in start_audio_datapath()
in case the data socket is already opened.

Added missing mutex around state updated in oput_write()
and in_read()

Made read and write code symmetric.

Bug: 28727517
Change-Id: I68d7fe63f298bbd1e387ec42fdb1277b2dcdfef5