Enable NoHistoryIfEncryptionEnabled test

The test was disabled for a long time. Let's try to re-enable it to see
if still flaky.

Bug: 1028968
Change-Id: Iee93b57cb6941ecb386751856136bf8deea0a5e3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2568283
Commit-Queue: Maksim Moskvitin <mmoskvitin@google.com>
Commit-Queue: Rushan Suleymanov <rushans@google.com>
Auto-Submit: Maksim Moskvitin <mmoskvitin@google.com>
Reviewed-by: Rushan Suleymanov <rushans@google.com>
Cr-Commit-Position: refs/heads/master@{#833262}

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

@@ -199,7 +199,7 @@ IN_PROC_BROWSER_TEST_F(TwoClientSessionsSyncTest, MultipleWindowsMultipleTabs) {
 }
 
 IN_PROC_BROWSER_TEST_F(TwoClientSessionsSyncTest,
-                       DISABLED_NoHistoryIfEncryptionEnabled) {
+                       NoHistoryIfEncryptionEnabled) {
   ASSERT_TRUE(SetupSync()) << "SetupSync() failed.";
 
   ASSERT_TRUE(CheckInitialState(0));