Fixed a Setting Bluetooth Airplane mode bug.

+ This patch moves the switch listeners from setup/teardown of the SwitchBar
to pause/resume of Bluetooth Settings.  This prevents Bluetooth from
receiving connect messages while Airplane mode is turning off Bluetooth
(which is what caused Bluetooth to re-enable.)

Bug: 17465951
Change-Id: I4d32fcf5bb3a2241ed03e2295c86390e15743954