Proper fix for zero signal strength and no_service. Fixes #2176141

Proper fix for zero signal strength and no_service. Fixes #2176141

Track phone service state changes and use a separate timer for out-of-service
since the hunting can timeout on some devices.

Store the timeout value in the config.xml, as it is device/network specific.

Settings App will also change to use the hunting duration to compute the cost
of zero signal.