Revert "Bluetooth: Check for mPanservice before changing tethering state"

This reverts commit f6b10f49, as
it actually breaks the error condition that's expected to happen
when a non-allowed app tries to toggle tethering

Ticket: CYNGNOS-432
Ticket: CYNGNOS-1403
(cherry picked from commit 346ac313)
(cherry picked from commit 089b9a52)
Change-Id: I197adee1f95657ce3072d2f9df343c3049413bbc