Do not show toggle for location tz detection in search.

It also makes setting in line with "Set time zone
automatically", which is rendered w/o toggle on search page.

Bug: 185906072
Test: manually verified that toggle is not shown
Test: m -j30 RunSettingsRoboTests ROBOTEST_FILTER="com.android.settings.datetime.LocationTimeZoneDetectionPreferenceControllerTest"
Change-Id: Ie71572c4a9b9bd6adf3660556363331e2943fd5b