GATT: Add handles for Gaming Audio Service (GMAS)

Allows GMAS to operate within the fixed range of handles.

Bug: 392846699
Bug: 353978074
Test: mmm packages/modules/Bluetooth
Flag: com.android.bluetooth.flags.leaudio_gmap_client
Change-Id: I5a1accfe164919ba73ff83f2d5eb068fa75b796c