Merge changes from topics "bluetooth_auto_on_basic_implementation", "bluetooth_auto_on_hidden_listener", "bluetooth_auto_on_system_api" into main

* changes:
  BluetoothSystemServer: add Hidden AutoOn metrics
  BluetoothSystemServer: add AutoOn user metrics counter
  BluetoothSystemServer: add AutoOn metrics counter
tree: c0e4920fcddc587206959f8a21ff5913f2a5948f
  1. stats/
  2. OWNERS