Change location settings "Device sensors" to "Device only" (b/10992469).

Note this is the minimum change for things visible to the user.
I double checked the accessibility string description and it is still
valid as is (it says "Use GPS to pinpoint your location").
We can also change the internal code variable names to not say "sensors"
but I would suggest doing this after KLP as is a noop in UI.

Change-Id: I2f747a42388a82e30c59b4b6e91849c5d590e1af