Make the fragment title can’t searchable

we shouldn't take users so deep into the settings IA because it's easy
to feel lost in settings after clicking on a result without additional
context.

Bug: 143055215
Test: robotest & manual
Change-Id: I337cb5ead31e1e4e7bf9be78132e90630f83ee43

tests/robotests/src/com/android/settings/accessibility/AutoclickPreferenceControllerTest.java

@@ -46,7 +46,7 @@ public class AutoclickPreferenceControllerTest {
     @Test
     public void getAvailabilityStatus_shouldReturnAvailableUnsearchable() {
         assertThat(mController.getAvailabilityStatus())
-                .isEqualTo(BasePreferenceController.AVAILABLE_UNSEARCHABLE);
+                .isEqualTo(BasePreferenceController.AVAILABLE);
     }
 
     @Test