LeAudio: Fix disconnect from settings

It might happen that the ACL is still connected when TA autoconnect
mechanism is used and the device reconnects immediately. To avoid that
we can force the ACL disconnection when the user intentionally
disconnects from the settings.

Bug: 285076926
Test: atest bluetooth_le_audio_client_test
Change-Id: I524b5bc130cb9bc4e30bff6691d845cc0dd7667b