Revert "Disable flaky ShouldKeepLocalDataOnTypeMismatch_E2ETest."

This reverts commit c7dc2cd8.

Reason for revert: FakeServer now logs more detailed failure logs
which could help debug the flakes, which otherwise don't repro
locally.

Original change's description:
> Disable flaky ShouldKeepLocalDataOnTypeMismatch_E2ETest.
> 
> This TwoClientPreferencesSyncTestWithSelfNotifications test case is
> flaky.
> 
> TBR=mastiz@chromium.org
> 
> Bug: 1012688
> Change-Id: I33f1956523be55f3f77db0560aac4c3de6721341
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1859635
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Reviewed-by: Mikel Astiz <mastiz@chromium.org>
> Commit-Queue: Lei Zhang <thestig@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#705625}

TBR=thestig@chromium.org,mastiz@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1012688
Change-Id: Ib12a81eb25ba2a335ead7a1b1316dfa7c2db2db8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893199Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712075}

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

@@ -222,10 +222,8 @@ class TwoClientPreferencesSyncTestWithSelfNotifications : public SyncTest {
   DISALLOW_COPY_AND_ASSIGN(TwoClientPreferencesSyncTestWithSelfNotifications);
 };
 
-// Flaky. https://crbug.com/1012688
-// This was E2E_ENABLED(ShouldKeepLocalDataOnTypeMismatch).
 IN_PROC_BROWSER_TEST_F(TwoClientPreferencesSyncTestWithSelfNotifications,
-                       DISABLED_ShouldKeepLocalDataOnTypeMismatch) {
+                       E2E_ENABLED(ShouldKeepLocalDataOnTypeMismatch)) {
   ResetSyncForPrimaryAccount();
   // Client 1 has type-conflicting data in it's pref file. Verify that incoming
   // values from sync of other type do not modify the local state.