Disable test LoginScreenAccessibilityPolicyBrowsertest.DeviceLoginScreenFullScreenMagnifier

LoginScreenAccessibilityPolicyBrowsertest.DeviceLoginScreenFullScreenMagnifier
is flaky from 10/18 on ChromeOS.
https://analysis.chromium.org/p/chromium/flake-portal/flakes/occurrences?key=ag9zfmZpbmRpdC1mb3ItbWVycAsSBUZsYWtlImVjaHJvbWl1bUBicm93c2VyX3Rlc3RzQExvZ2luU2NyZWVuQWNjZXNzaWJpbGl0eVBvbGljeUJyb3dzZXJ0ZXN0LkRldmljZUxvZ2luU2NyZWVuRnVsbFNjcmVlbk1hZ25pZmllcgw

TBR=amraboelkher@google.com

Bug: 1015763
Change-Id: I73451c082190a275a75e78ca5d6134a0c369d530
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1869669Reviewed-by: Lan Wei <lanwei@chromium.org>
Commit-Queue: Lan Wei <lanwei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707470}

chrome/browser/chromeos/policy/login_screen_accessibility_policy_browsertest.cc

@@ -919,8 +919,9 @@ IN_PROC_BROWSER_TEST_F(LoginScreenAccessibilityPolicyBrowsertest,
   EXPECT_FALSE(accessibility_manager->IsFocusHighlightEnabled());
 }
 
+// TODO(crbug.com/1015763): Flaky on ChromeOS.
 IN_PROC_BROWSER_TEST_F(LoginScreenAccessibilityPolicyBrowsertest,
-                       DeviceLoginScreenFullScreenMagnifier) {
+                       DISABLED_DeviceLoginScreenFullScreenMagnifier) {
   // Verifies that the state of the full-screen magnifier accessibility
   // feature on the login screen can be controlled through device policy.
   chromeos::MagnificationManager* magnification_manager =