Skip empty bluetooth-page in QS when bluetooth is disallowed

If DISALLOW_BLUETOOTH is set, tapping bluetooth in QS used to
open the empty device-selection screen with an untoggable switch.
Now, it directly brings you to the settings page with policy
transparency, mirroring the behaviour of DISALLOW_CONFIG_BLUETOOTH.

Bug: 32895313
Test: manual

Change-Id: I77230532428a4dd2a7769aa73dcc195c51312c36