Bluetooth: sdp: a2dp fuzzer coverage improvement

Improve fuzzing coverage by resolving the most prominent
early back-offs by the fuzzer.

A2DP is only accepting two distinct values for
service_uuid, and because the argument is uint16
this api is left unexplored by the fuzzer.

Similar goes for attr_id, although there are many more
acceptable values, having ATTR_ID_BT_PROFILE_DESC_LIST
appear more often helps unlock the use of complex
structures within SDP attributes database.

Bug: 257060629
Test: fuzzer builds and runs
Change-Id: I23871d2c15054eaf56ccc25519954b4885cfcfd9