[Sheriff] Disable SingleClientWalletSyncTest.NewSyncDataShouldReplaceExistingData

Test is flaky:
https://ci.chromium.org/p/chromium/builders/ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/36522

Bug: 997786
Change-Id: I97f2e400e829b13859033767a257402325646cf3
NoTry: True
Tbr: treib@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1983441Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727648}

chrome/browser/sync/test/integration/single_client_wallet_sync_test.cc

@@ -520,8 +520,9 @@ IN_PROC_BROWSER_TEST_F(SingleClientWalletSyncTest, ClearOnSignOut) {
 
 // Wallet is not using incremental updates. Make sure existing data gets
 // replaced when synced down.
+// TODO(crbug.com/997786): Test is flaky.
 IN_PROC_BROWSER_TEST_F(SingleClientWalletSyncTest,
-                       NewSyncDataShouldReplaceExistingData) {
+                       DISABLED_NewSyncDataShouldReplaceExistingData) {
   GetFakeServer()->SetWalletData(
       {CreateSyncWalletCard(/*name=*/"card-1", /*last_four=*/"0001",
                             kDefaultBillingAddressID),