bt: Unset multi channel bit for 44.1/88.2Khz A2DP Rx

When opening port for 44.1/88.2KHz A2DP Rx, explicitly
unset multi channel bit. This is required because for SCO/A2DP
with other sample rates, we set the multi channel bit. The
bit remains set even after the channel is removed and until we
expliciltly unset again.

Change-Id: I76d7a46b107baf811657b7ade307a7dd60a21c4a
Signed-off-by: gaoxiang <quic_gaoxiang@quicinc.com>