leaudio: Fix LE_AUDIO profile re-connect

Bug: 218534441
Tag: #feature
Sponsor: rlukasz@
Test: atest --host bluetooth_le_audio_client_test

Issue: LE_AUDIO profile was not seen to reconnect automatically
even when the device is reachable after a remote initiated
disconnection or disconnection due to timeout. Other profile
(VC) re-connected fine in these scenarios.

Fix- Added background reconnection request during disconnect
handling (if the disconnection is not intended by local host).

This change will help with reconnect in below scenarios
1. Peer device went out of range and later came back in range
2. Peer device is put into cradle (lid closed) and later
   taken out of cradle.

Note: Restoration of below merged-and-reverted-later gerrit
Iac25b1f9c:le_audio : Fix issue of LE Audio not connecting af...



Change-Id: I31451ba3dbef0af2e75d82070ccb7234266094be