Fix uncaught exception when no location provider available

Change-Id: I2625e6d219401a04a372a487d84edaaf3099f0d6
Dialer: Fix NPE in CallStats

Change-Id: I0eed1e66f803e072c58d85c78c253730f81f029d
See: https://jira.cyanogenmod.org/browse/BUGDUMP-114773?jql=text%20~%20%22Callstats%22