Do not config A2DP codec priorities before retrieving all capabilities

* In current A2DP design, if Java A2DP service disabled optional
  codec and invoke native SetCodecUserConfig() while our get codec
  capabilities process is not finished, stack would raise SBC
  priority to 1000000 without notifying the remote device. This
  behavior would cause phone and the remote headset using different
  codec while A2DP streaming and lead to no sound problem.
* We should always check the codec capabilities status before changing
  the codec priority.

Bug: 124254557
Test: manual

Change-Id: I19693ecdd581836829c15ae37d579a4cb3ac0200