Revert "Test Fix SettingRobolectricTest Fail"

This reverts commit 818f77cd1f.

Reason for revert: Underlying issue fixed in ag/23454315.

Bug: b/275023433
Test: atest SettingsGlobalRoboTests

Change-Id: I1af272efd00b3c5bd35310512f5712d5d1c7d834

tests/robotests/src/com/android/settings/theme/ContrastPreferenceControllerTest.java

@@ -38,7 +38,6 @@ import androidx.preference.Preference;
 import androidx.test.core.app.ApplicationProvider;
 
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -74,7 +73,6 @@ public class ContrastPreferenceControllerTest {
         assertThat(mController.getAvailabilityStatus()).isEqualTo(AVAILABLE);
     }
 
-    @Ignore
     @Test
     public void testHandlePreferenceTreeClick() {
         Preference preference = new Preference(mContext);