SystemUI: Set usesPermissionFlags="neverForLocation"

System UI requires BT permissions in order to present device
state to users, and these permissions are never used to derive
user location.

This change also removes the COARSE_LOCATION permission that
was added in commit a8610172 to receive BluetoothDevice.ACTION_FOUND
broadcasts. This is no longer necessary.

Test: atest SystemUITests
Bug: 187069003

Change-Id: I0c9e6603aeb99d3ccfc21d4e26314740e08cf166