Settings: Fix switch state being out of sync.

    - Since QS Tile can also set state of Heads up now,
    we have to set a content observer for the action bar
    switch.

Change-Id: I1c63fd2627a0f823eb6982456e1ed79ab84d1957
Automatic translation import

Change-Id: Icb77a2c1f07d2e54f64928f32f0b16482772fe47