AudioDeviceBroker: mute call when switching LE Audio device

When a Bluetooth LE Audio device is disconnected as part of a device switch,
mute call until LE Audio is selected for call or a 2 second timeout happens.

Bug: 414444196
Test: repro steps in bug
Flag: com.android.media.audio.optimize_bt_device_switch
Change-Id: I6c257e1b451358b68ce1a6228dedc8d1a0974fb9