Disable flaky ManageSpaceActivity#testClearUnimportantOnly

BUG=1060975
TBR=dmurph@chromium.org

Change-Id: I288bacd1a18db0a30e2c2c7b36acd6966c2f02f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2106388Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751384}

chrome/android/javatests/src/org/chromium/chrome/browser/site_settings/ManageSpaceActivityTest.java

@@ -21,6 +21,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import org.chromium.base.test.util.CommandLineFlags;
+import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.MinAndroidSdkLevel;
 import org.chromium.base.test.util.RetryOnFailure;
@@ -117,6 +118,7 @@ public class ManageSpaceActivityTest {
     @MediumTest
     @RetryOnFailure
     @Feature({"SiteEngagement"})
+    @DisabledTest(message = "https://crbug.com/1060975")
     public void testClearUnimportantOnly() throws Exception {
         final String cookiesUrl =
                 mTestServer.getURL("/chrome/test/data/android/storage_persistance.html");