Update summary for WifiTetherDisablePreference accordingly

The summary of this preference is depenent on other two preferences for
USB tether and Bluetooth tether. The summary is updated accordingly.

Bug: 146818850
Test: CodeInspectionTest, WifiTetherDisablePreferenceControllerTest,
manually test.

Change-Id: I366d10a43814ea0d7def466b1976928f17875029

res/values/strings.xml

@@ -3744,6 +3744,14 @@
     <!-- Tethering controls, footer note displayed when tethering is disabled because Data Saver mode is on [CHAR LIMIT=none]-->
     <string name="tether_settings_disabled_on_data_saver">"Can\u2019t tether or use portable hotspots while Data Saver is on"</string>
 
+    <!-- Disable Wifi Hotspot option-->
+    <!-- Don't use Wi-Fi hotspot summary when USB tethering is chosen [CHAR LIMIT=NONE]-->
+    <string name="disable_wifi_hotspot_when_usb_on">Only share internet via USB</string>
+    <!-- Don't use Wi-Fi hotspot summary when Bluetooth tethering is chosen [CHAR LIMIT=NONE]-->
+    <string name="disable_wifi_hotspot_when_bluetooth_on">Only share internet via Bluetooth</string>
+    <!-- Don't use Wi-Fi hotspot summary when USB tethering and Bluetooth tethering are chosen [CHAR LIMIT=NONE]-->
+    <string name="disable_wifi_hotspot_when_usb_and_bluetooth_on">Only share internet via USB and Bluetooth</string>
+
     <!-- USB Tethering options -->
     <string name="usb_title">USB</string>
     <string name="usb_tethering_button_text">USB tethering</string>

res/xml/all_tether_prefs.xml

@@ -74,6 +74,7 @@
         <SwitchPreference
             android:key="disable_wifi_tethering"
             android:title="Don't use Wi-Fi hotspot"
+            android:summary="@string/summary_placeholder"
             settings:controller="com.android.settings.network.WifiTetherDisablePreferenceController"
             settings:keywords="@string/keywords_hotspot_tethering" />
     </PreferenceCategory>

src/com/android/settings/network/WifiTetherDisablePreferenceController.java

@@ -30,6 +30,7 @@ import androidx.preference.PreferenceScreen;
 import androidx.preference.SwitchPreference;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.settings.R;
 import com.android.settings.core.BasePreferenceController;
 import com.android.settingslib.TetherUtil;
 
@@ -95,8 +96,14 @@ public final class WifiTetherDisablePreferenceController extends BasePreferenceC
 
     @Override
     public CharSequence getSummary() {
-        // TODO(b/146818850): Update summary accordingly.
+        if (mUSBTetherEnabled && mBluetoothTetherEnabled) {
-        return super.getSummary();
+            return mContext.getString(R.string.disable_wifi_hotspot_when_usb_and_bluetooth_on);
+        } else if (mUSBTetherEnabled) {
+            return mContext.getString(R.string.disable_wifi_hotspot_when_usb_on);
+        } else if (mBluetoothTetherEnabled) {
+            return mContext.getString(R.string.disable_wifi_hotspot_when_bluetooth_on);
+        }
+        return mContext.getString(R.string.summary_placeholder);
     }
 
     @Override