[Settings] Support getSystemService(Class<T>)

Add getSystemService(Class<T>) to align the capability with framework
part.

Bug: 179640862
Test: local
Change-Id: I278951c2402aa8551cee37923f45626ab1830dd3

src/com/android/settings/SettingsPreferenceFragment.java

@@ -438,6 +438,13 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
         return getActivity().getSystemService(name);
     }
 
+    /**
+     * Returns the specified system service from the owning Activity.
+     */
+    protected <T> T getSystemService(final Class<T> serviceClass) {
+        return getActivity().getSystemService(serviceClass);
+    }
+
     /**
      * Returns the PackageManager from the owning Activity.
      */