Restart Wi-Fi tethering automatically if configuration change

- When the Wi-Fi Hotspot is already started, if the user changes the configuration, the Wi-Fi Hotspot will be restarted automatically.

- When the Wi-Fi hotspot restarts, display a circle on the screen to indicate that it is processing.

Bug: 245258763
Test: manual test
atest -c WifiTetherSettingsTest \
         WifiHotspotSpeedSettingsTest
atest -c WifiHotspotRepositoryTest \
         WifiHotspotSecuritySettingsTest \
         WifiHotspotSecurityViewModelTest \
         WifiHotspotSpeedViewModelTest \
         WifiTetherViewModelTest

Change-Id: I6fdd5892916703095f28d0589ebc3b7dd59fcd61

src/com/android/settings/wifi/tether/WifiHotspotSecurityViewModel.java

@@ -129,6 +129,13 @@ public class WifiHotspotSecurityViewModel extends AndroidViewModel {
         mViewInfoListData.setValue(mViewItemMap.values().stream().toList());
     }
 
+    /**
+     * Gets Restarting LiveData
+     */
+    public LiveData<Boolean> getRestarting() {
+        return mWifiHotspotRepository.getRestarting();
+    }
+
     /**
      * Wi-Fi Hotspot View Item
      */