MediaControl: Allow basic GATT ops before authorized by LeAudioService

Before authorized by LeAudioService, the device should be able to read
GATT attributes without errors, but will get just some basic inf and
filtered-out data. This is to prevent some of the devices to giving up
on MCP control when they receive the first unathorized error response
for GATT operation on MCS.

Bug: 282938041
Test: atest BluetoothInstrumentationTests
Change-Id: I1bc365ab3a7cff662a7480fa2b895024cdd2c93c