Remove descriptors of unbonded device

When ACTION_LE_AUDIO_CONNECTION_STATE_CHANGED
is sent before ACTION_BOND_STATE_CHANGED is sent,
the state machine is removed but the device descriptor
is not removed from the hash map.

Which could cause NPE in dumpsys.

We could repro this by forgetting LE audio device
multiple times.

This CL ensures the device descriptor is removed when
the state machine is removed.

Tag: #feature
Bug: 269969529
Test: manually forgetting LE devices and see dumpsys
and atest BluetoothInstrumentationTests

Change-Id: I0f9afe8ebb1712dd03b4072fe6f42a37919bb3c1