Dismiss the dialog in onDestroy so that it doesn't leak on orientation change or other transitions.

src/com/android/settings/ApplicationSettings.java

@@ -52,6 +52,14 @@ public class ApplicationSettings extends PreferenceActivity implements
         }
     }
 
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        if (mWarnInstallApps != null) {
+            mWarnInstallApps.dismiss();
+        }
+    }
+
     @Override
     public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
         if (preference == mToggleAppInstallation) {