LeAudioService: Fix bonding with lead device

This patch adds some additional logs around lead device handling.
This patch also make sure to disconnect lead device if the disconnection
was due to unbonding process

Bug: 242645864
Test: atest BluetoothInstrumentationTests
Tag: #feature
Change-Id: If860e8aeea608fc78d33e89b0e2b544bdf7a84d2