[Settings] 1. Add configChange for WFC Activity to cover the changes of rotation and screen size
2. register split rule for MobileNetworkActivity

Bug: 204508876
Test: manual
Change-Id: Iff3dae41293e79b274d2928cb51efea46fb45dd4
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 69f382c..e4e1a10 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -3337,6 +3337,7 @@
         <activity
             android:name="Settings$WifiCallingSettingsActivity"
             android:exported="true"
+            android:configChanges="orientation|keyboard|keyboardHidden|screenSize|smallestScreenSize|screenLayout"
             android:label="@string/wifi_calling_settings_title">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />