Add calendar sliding windows setting.
Add calendar sliding windows setting.

GOOGLE_CALENDAR_SYNC_WINDOW_UPDATE_DAYS indicates how often to update
the calendar sync window.

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base