[iOS] Disable NoOverlappingPresentedViewControllers for devices.

TBR=mrefaat@chromium.org

Bug: 968514
Change-Id: Iebf1d852deac28a8946c1529f5cdd537a427d5f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1637405Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664749}

ios/chrome/browser/store_kit/store_kit_coordinator_unittest.mm

@@ -144,7 +144,15 @@ TEST_F(StoreKitCoordinatorTest, NoOverlappingStoreKitsPresented) {
 
 // Tests that if the base view controller is presenting any view controller,
 // starting the coordinator doesn't present new view controller.
-TEST_F(StoreKitCoordinatorTest, NoOverlappingPresentedViewControllers) {
+// TODO:(crbug.com/968514): Re-enable this test on devices.
+#if TARGET_OS_SIMULATOR
+#define MAYBE_NoOverlappingPresentedViewControllers \
+  NoOverlappingPresentedViewControllers
+#else
+#define MAYBE_NoOverlappingPresentedViewControllers \
+  FLAKY_NoOverlappingPresentedViewControllers
+#endif
+TEST_F(StoreKitCoordinatorTest, MAYBE_NoOverlappingPresentedViewControllers) {
   NSString* kTestITunesItemIdentifier = @"TestITunesItemIdentifier";
   coordinator_.iTunesProductParameters = @{
     SKStoreProductParameterITunesItemIdentifier : kTestITunesItemIdentifier,