BluetoothInCallService enabled state setting modification

This patch is to modify component enabled setting flow of
BluetoothInCallService. Instead of disabling BluetoothInCallService when
exiting ON state of Bluetooth adapter, disabling
BluetoothInCallService in its onDestroy callback to avoid component been
disabled without unbind.

Tag: #stability
Bug: 195882442
Test: HFP regression test; atest BluetoothInstrumentationTests
Change-Id: Id4719d5144dce15b77fab4293749ee9699e42830