Don't ignore the A2DP Sink preferred SBC codec config

If the A2DP Sink device sends "Set Configuration" with its preferred
SBC configuration, try using that configuration when selecting
the codec parameters instead of the A2DP Sink SBC capability.

Test: A2DP streaming, PTS AVDTP Tests: TC_ACP_SRC_SIG_SMG_BV_18_C,
      TC_ACP_SRC_SIG_SMG_BV_20_C, TC_ACP_SRC_SIG_SMG_BV_22_C
      PTS A2DP Tests: A2DP/SRC/SET/BV-04-I, A2DP/SRC/SET/BV-06-I
Bug: 37723311
Bug: 35664023
Change-Id: I48e2aa664b899c1cda5df4d1f86f9cfa3a9a67f6