ABS volume support is not informed to Audio sometimes

Local and peer may initiate the AVRCP connection at the same time.
As initiator, DUT does SDP discovery firstly. During the SDP discovery,
the AVRCP profile connection initiated from peer could have finshed
ahead. Then as acceptor, DUT initiate SDP discovery again. Due to the SDP
discovery has already been ongoing, the new request is ignored. After
SDP discovery completed, as initiator, DUT iniates the AVRCP profile
connection as well but fail due to AVRCP profile connection already exist.
Thus both procedure are stuck in the intermediate state. Hence neither
do abs volume registration and inform the ASB support to uplayer.
After SDP completed, DUT should check whether the AVRCP connection is
already exist. If yes, just skip the AvrcpConnect and proceed to abs
volume registration.

Bug: 335331242
Test: m com.android.btservices
Test with Bose Soundlink Mini, confirm that the avrcp abs volume can be
correctly informed to audio no matter connection conflict happen or not.

Change-Id: Ibe374f6e8c85f2c8cf5923b680fd2ab673ddc04a