Revert "Disable test flaky RecommendAppsScreenTest.ParseError"

This reverts commit cff91b98.

Reason for revert: The issue should've been fixed with CL:1868769

Original change's description:
> Disable test flaky RecommendAppsScreenTest.ParseError
> 
> RecommendAppsScreenTest.ParseError is very flaky on ChromeOS
> since 2019/10/16.
> 
> https://analysis.chromium.org/p/chromium/flake-portal/flakes/occurrences?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSBUZsYWtlIjljaHJvbWl1bUBicm93c2VyX3Rlc3RzQFJlY29tbWVuZEFwcHNTY3JlZW5UZXN0LlBhcnNlRXJyb3IM&show_all_occurrences=1
> 
> TBR=tbarzic@chromium.org
> 
> Bug: 1015013
> Change-Id: Ia93fcd4624b6c35fae4e53c740e415e3a28f9b41
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1867469
> Reviewed-by: Lan Wei <lanwei@chromium.org>
> Commit-Queue: Lan Wei <lanwei@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#707140}

TBR=lanwei@chromium.org

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

Bug: 1015013
Change-Id: I88411768f64de6b92e2bdcba74459dd55f736040
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1872584Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Roman Sorokin [CET] <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708117}

chrome/browser/chromeos/login/screens/recommend_apps_screen_browsertest.cc

@@ -605,8 +605,7 @@ IN_PROC_BROWSER_TEST_F(RecommendAppsScreenTest, DISABLED_NoRecommendedApps) {
   EXPECT_EQ(base::Value(base::Value::Type::LIST), *fast_reinstall_packages);
 }
 
-// Disabled due to flakiness: https://crbug.com/1015013
-IN_PROC_BROWSER_TEST_F(RecommendAppsScreenTest, DISABLED_ParseError) {
+IN_PROC_BROWSER_TEST_F(RecommendAppsScreenTest, ParseError) {
   recommend_apps_screen_->Show();
 
   OobeScreenWaiter screen_waiter(RecommendAppsScreenView::kScreenId);