Fix UI flicker problem and update wordings

    <!-- Date & time setting screen setting switch title: whether the system clock (Unix epoch time) should be determined automatically [CHAR LIMIT=100] -->

    <string name="date_time_auto">Set time automatically</string>

    <!-- Date & time setting screen setting switch title: whether the time zone should be determined automatically [CHAR LIMIT=100]  -->

    <string name="zone_auto_title">Set time zone automatically</string>

    <string name="zone_auto_title">Set automatically</string>

    <!-- Date & time setting screen setting option summary text for the automatic 24 hour setting checkbox [CHAR LIMIT=100] -->

    <string name="date_time_24hour_auto">Use locale default</string>

    <!-- Date & time setting screen setting check box title [CHAR LIMIT=30] -->

    <string name="managed_profile_location_services">Location services for work</string>

    <!-- [CHAR LIMIT=60] Date&Time settings screen, toggle button title -->

    <string name="location_time_zone_detection_toggle_title">Use location to set time zone</string>

    <string name="location_time_zone_detection_toggle_title">Use location</string>

    <!-- [CHAR LIMIT=60] Date&Time settings screen, title of the dialog shown when user tries to

         enable GeoTZ when Location toggle is off. -->

    <string name="location_time_zone_detection_location_is_off_dialog_title">Device location needed</string>

    <!-- [CHAR LIMIT=NONE] Location settings screen, summary when location time zone detection is not

         allowed for the user, e.g. because of device policy -->

    <string name="location_time_zone_detection_not_allowed">Location time zone detection changes are not allowed</string>

    <!-- [CHAR LIMIT=NONE] Location settings screen, summary when location time zone detection is enabled. -->

    <string name="location_time_zone_detection_auto_is_on">Location may be used to set time zone</string>

    <!-- [CHAR LIMIT=30] Security & location settings screen, setting check box label for Google location service (cell ID, wifi, etc.) -->

    <string name="location_network_based">Wi\u2011Fi &amp; mobile network location</string>

        <com.android.settingslib.RestrictedSwitchPreference

            android:key="auto_zone"

            android:title="@string/zone_auto_title"

            settings:allowDividerAbove="true"

            settings:userRestriction="no_config_date_time"/>

        <!-- This preference gets removed if location-based time zone detection is not supported -->

            // If capability is possessed, toggle status already tells all the information needed.

            // Returning null will make previous text stick on toggling.

            // See AbstractPreferenceController#refreshSummary.

            return "";

            summaryResId = R.string.location_time_zone_detection_auto_is_on;

        } else {

            // This is unexpected: getAvailabilityStatus() should ensure that the UI element isn't

            // even shown for known cases, or the capability is unknown.

                new TimeZoneCapabilitiesAndConfig(capabilities, configuration);

        when(mTimeManager.getTimeZoneCapabilitiesAndConfig()).thenReturn(capabilitiesAndConfig);

        assertThat(mController.getSummary().toString()).isEmpty();

        assertThat(mController.getSummary()).isEqualTo(

                mContext.getString(R.string.location_time_zone_detection_auto_is_on));

    }

    @Test