Re-enable PermissionManager tests (#6293)

Author: cmelchior

realm/realm-library/src/syncIntegrationTest/java/io/realm/PermissionManagerTests.java

@@ -55,7 +55,6 @@
 import static org.junit.Assert.fail;
 
 @RunWith(AndroidJUnit4.class)
-@Ignore // FIXME: Temporary disable unit tests due to lates (3.0.0-alpha.2) ROS having issues. Re-enable once ROS is stable again.
 public class PermissionManagerTests extends StandardIntegrationTest {
 
     private SyncUser user;