Kill the Switch on top-right after exiting Accounts & sync.

Bug: 5564377  - Bluetooth screen showing a Switch that doesn't follow
the bluetooth setting.

This seems to have been the Switch in Accounts & sync being set as a
custom view for the Settings activity and not removed on changing
fragments.

Change-Id: I4575a769fbf5482048dbc4e912c6b6f782f505a0