Disable flakey testShow_SingleAsHomepage_V2

TBR: gogerald@google.com
Bug: 1139467
Change-Id: Ic3903e33348bd653ebdd076ca56fbae72188fb44
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2481547Reviewed-by: Sky Malice <skym@chromium.org>
Commit-Queue: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818122}

chrome/android/features/start_surface/internal/javatests/src/org/chromium/chrome/features/start_surface/StartSurfaceTest.java

@@ -645,6 +645,7 @@ public class StartSurfaceTest {
     // clang-format off
     @CommandLineFlags.Add({BASE_PARAMS + "/single/exclude_mv_tiles/true" +
         "/show_last_active_tab_only/true/show_stack_tab_switcher/true"})
+    @DisabledTest(message = "https://crbug.com/1139467")
     public void testShow_SingleAsHomepage_V2() {
         // clang-format on
         if (!mImmediateReturn) {