Mark PageInfoViewTest#testShowCookiesSubpage as flaky.

Bug: 1156285
Change-Id: Ib2abc6d9524fde559d52be9c8498fa3868bad355
TBR: dullweber@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2574987Reviewed-by: Balazs Engedy <engedy@chromium.org>
Commit-Queue: Balazs Engedy <engedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834667}

chrome/android/javatests/src/org/chromium/chrome/browser/page_info/PageInfoViewTest.java

@@ -383,6 +383,7 @@ public class PageInfoViewTest {
     @MediumTest
     @Feature({"RenderTest"})
     @Features.EnableFeatures(PageInfoFeatureList.PAGE_INFO_V2)
+    @FlakyTest(message = "https://crbug.com/1156285")
     public void testShowCookiesSubpage() throws IOException {
         mActivityTestRule.startMainActivityOnBlankPage();
         setThirdPartyCookieBlocking(CookieControlsMode.BLOCK_THIRD_PARTY);