Settings: updating policy list after switching mobile data switch

Removed unnecessary call to updatePolicy() in the mDataEnabledListener since the setMobileDataEnabled() method already calls it.
Calling updatePolicy() with refreshCycle to true, so that the "change cycle..." option is enabled/disabled correctly

Change-Id: I2f8cfd898e663b644576626f00e38fff3ec0bbd8

Conflicts:
	src/com/android/settings/DataUsageSummary.java