Listen for weather update notifications instead of polling.
Listen for weather update notifications instead of polling.

DeskClock still periodically requests updated information
from the weather content provider (as recommended by the
Genie team) but does so on an hourly schedule rather than
every 5 minutes.

Also addresses http://b/2314820.

OrBin/SynClock-Android,dseuss/deskclock,dseuss/deskclock