Revert "[Sheriff] Disable graphics.TraceReplay.glxgears_stable"

This reverts commit 8f840cb8.

Reason for revert: The tests, as reported, should pass now.

Original change's description:
> [Sheriff] Disable graphics.TraceReplay.glxgears_stable
> 
> It has been failing consistently on CrOS bots.
> This disables it.
> 
> Bug: 1123872
> Change-Id: I79152a991118af02a215e3f809c50f42c12d24cd
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2387101
> Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
> Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#803459}

TBR=emaxx@chromium.org,mamir@chromium.org

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

Bug: 1123872
Change-Id: I676d000fb95648985a533b1ef860d50dedf7d129
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2404580Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805858}

chromeos/BUILD.gn

@@ -289,9 +289,6 @@ if (is_chromeos_device) {
   tast_test("chrome_all_tast_tests") {
     # To disable a specific test, add it the following list and cite a bug.
     tast_disabled_tests = [
-      # crbug.com/1123872
-      "graphics.TraceReplay.glxgears_stable",
-
       # crbug.com/1123300
       "crostini.Basic.artifact",
       "crostini.PackageInfo.artifact",