Chronus: Location provider fixes and cleanup

This commit switches Chronus to only use the Passive location
provider and adds the FINE location permission.  It also includes
some general cleanup and better handling of the setting of a
custom location, fixing a NPE and ensuring the summary text is
updated correctly.

Change-Id: Ic3e870eefb66b0b81fa45ab9da6b3a8b04e63334