Show pop-up banner when Location is off and user tries to enable GeoTZ.

As of now GeoTZ state remains unchanged even if user enables
Location toggle.

Bug: 152746236
Test: m -j30 RunSettingsRoboTests ROBOTEST_FILTER="com.android.settings.datetime.LocationTimeZoneDetectionPreferenceControllerTest"
Test: checked manually that dialog opens Location settings page
Change-Id: I5fd3288e9d5a7aac3bc82da6944b4ccd6bb9e0f5