Restrict DUT supported SBC configuration in GET_CAP response

DUT shows all possible SBC configurations as supported
as part of GET_CAP response and also allows AV SINK to
opt for any of these values from that set as part of
SET_CONFIG request, but later opts for only recommended
figures while streaming so that leads to mismatch in
configuration between the config values SINK sets during
SET_CONFIG and config values DUT chooses for streaming
and hence it causes PTS (version 6.4 onwards) certification
failure for below A2DP and AVDTP cases:

A2DP:
TC_SRC_SET_BV_04_I
TC_SRC_SET_BV_06_I

AVDTP:
TC_ACP_SRC_SIG_SMG_BV_18_C
TC_ACP_SRC_SIG_SMG_BV_20_C
TC_ACP_SRC_SIG_SMG_BV_22_C

Restricting DUT supported SBC configurations to reflect only
the configuration DUT opts for during streaming makes sure
remote also opts for those config values during SET_CONFIG
and later there is no mismatch.

Change-Id: I13dbe94e0ca52708fc62c6db7513f7985237c18c