leaudio: Additional improvement to handle no available context types

When no context is available, LeAudio device will not be able to stream
anything.
This patch makes sure that ActiveDeviceManager will not use
LeAudioDevice when it is not available for streaming.
Also, native code makes sure to update Java with available contexts
before notifing about device being Connected. In this way, when
ActiveDeviceManager gets connected callback, it will have all the
information to decide if device can be used for streaming or not.

Bug: 333830497
Bug: 314677565
Test: atest LeAudioServiceTest ActiveDeviceManagerTest
bluetooth_le_audio_client_test
Flag: Exempt, easy fix, regression tested with unit tests, new unit test
added

Change-Id: Iace0bbe278f8fc99e8f8b0ffda888538dda12ee1