Remove getExtraAction() from DashboardFeatureProvider.

It's always set to null and not doing anything.

Bug: 111427617
Test: robotest
Change-Id: I7172a31056950b1597f0b98625a3a2615305e466

tests/robotests/src/com/android/settings/dashboard/DashboardFeatureProviderImplTest.java

@@ -365,11 +365,6 @@ public class DashboardFeatureProviderImplTest {
         assertThat(launchIntent).isNull();
     }
 
-    @Test
-    public void testGetExtraIntentAction_shouldReturnNull() {
-        assertThat(mImpl.getExtraIntentAction()).isNull();
-    }
-
     @Test
     public void openTileIntent_profileSelectionDialog_shouldShow() {
         final Tile tile = new Tile(mActivityInfo, CategoryKey.CATEGORY_HOMEPAGE);