[Sheriff] disable UnifiedAutoplaySettingBrowserTest.DefaultAllow

Flake portal:
https://analysis.chromium.org/p/chromium/flake-portal/flakes/occurrences?key=ag9zfmZpbmRpdC1mb3ItbWVyUAsSBUZsYWtlIkVjaHJvbWl1bUBicm93c2VyX3Rlc3RzQFVuaWZpZWRBdXRvcGxheVNldHRpbmdCcm93c2VyVGVzdC5EZWZhdWx0QWxsb3cM

TBR=sergeyu@chromium.org

Bug: 1101524
Change-Id: I81a5e4e4f8c175c88cda9be3e80285c790ab8c04
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2303124Reviewed-by: Sahel Sharify <sahel@chromium.org>
Commit-Queue: Sahel Sharify <sahel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789219}

chrome/browser/media/unified_autoplay_browsertest.cc

@@ -562,7 +562,8 @@ IN_PROC_BROWSER_TEST_F(UnifiedAutoplaySettingBrowserTest, Block_Wildcard) {
   EXPECT_FALSE(AutoplayAllowed(main_frame()));
 }
 
-IN_PROC_BROWSER_TEST_F(UnifiedAutoplaySettingBrowserTest, DefaultAllow) {
+// Flaky. See https://crbug.com/1101524.
+IN_PROC_BROWSER_TEST_F(UnifiedAutoplaySettingBrowserTest,  DISABLED_DefaultAllow) {
   GURL main_url(
       embedded_test_server()->GetURL("example.com", kFramedTestPagePath));
   GURL foo_url(embedded_test_server()->GetURL("foo.com", kFramedTestPagePath));