Floss: validate connection state in bluetooth_media

It is discovered that in some cases a profile-disconnection request may
be received when it was not connected. This will serve as a false alarm
that would cause the device to be removed from the audio stack.

In this CL, we validate the connection state so that if the connection
state already matches what was requested, we will just ignore it.

Bug: 248325887
Tag: #floss
Test: Build and verify
Change-Id: I5a784c81fc8d5dc01057f921a1e998954c570a8a