use shim api directly

Get rid of pass-through methods:
BTM_AcceptlistAddDirect
BTM_AcceptlistRemove
BTM_AcceptlistClear

Move btm_update_scanner_filter_policy to only place where it's used.

Test: mma -j32;
Bug: 372202918
Flag: exempt, removing intermidiate layer, no logical change
Change-Id: I8c4a02875c7c28fc176644d45bebf0c29a2aafa2