Setup external/robolectric for SettingsRoboTests

Current failing tests: ab/I64100010182936387
Had to Ignore some of com.android.settings.accessibility tests, which will be fixed separately

Bug: 261728063
Test: atest SettingsRoboTests -- --test-arg com.android.tradefed.testtype.IsolatedHostTest:java-flags:-XX:CompressedClassSpaceSize=3g

Change-Id: I4a0cb992db924936826e0c9808accc78dddb5f30

tests/robotests/src/com/android/settings/inputmethod/TrackpadBottomPreferenceControllerTest.java

@@ -40,9 +40,13 @@ import org.junit.runner.RunWith;
 import org.mockito.junit.MockitoJUnit;
 import org.mockito.junit.MockitoRule;
 import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
 
 /** Tests for {@link TrackpadBottomPreferenceController} */
 @RunWith(RobolectricTestRunner.class)
+@Config(shadows = {
+        com.android.settings.testutils.shadow.ShadowSystemSettings.class,
+})
 public class TrackpadBottomPreferenceControllerTest {
     @Rule
     public MockitoRule rule = MockitoJUnit.rule();