sheriff: Disable flaky NewTabPageTest#testMemoryPressure__EnableInterestFeed

TBR=huayinz@chromium.org

Bug: 909978
Change-Id: I9347d3f4c344ab19cffa3f3148dc26b557f1a724
Reviewed-on: https://chromium-review.googlesource.com/c/1354729Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612066}

chrome/android/javatests/src/org/chromium/chrome/browser/ntp/NewTabPageTest.java

@@ -663,6 +663,7 @@ public class NewTabPageTest {
     }
 
     @Test
+    @DisabledTest(message = "https://crbug.com/909978")
     @SmallTest
     @Feature({"NewTabPage", "FeedNewTabPage"})
     @ParameterAnnotations.UseMethodParameter(InterestFeedParams.class)