Incorrect panel layout after rotation

-Handle onConfigurationChanged and force to update layout
-Add test case

Bug: 144751509
Test: make -j42 RunSettingsRoboTests
Change-Id: Ic170d4f6f045299c0520e899e06b5b4e9f009643

tests/robotests/src/com/android/settings/panel/SettingsPanelActivityTest.java

@@ -31,6 +31,7 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.os.Build;
 import android.view.Window;
 import android.view.WindowManager;
@@ -139,4 +140,12 @@ public class SettingsPanelActivityTest {
         assertThat(paramCaptor.getValue().privateFlags
                 & SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS).isEqualTo(0);
     }
+
+    @Test
+    public void onConfigurationChanged_shouldForceUpdate() {
+        mSettingsPanelActivity.mForceCreation = false;
+        mSettingsPanelActivity.onConfigurationChanged(new Configuration());
+
+        assertThat(mSettingsPanelActivity.mForceCreation).isTrue();
+    }
 }