Bug 1668892: Disable operator-dictionary-spacing-004.html Operator dictionary...

Bug 1668892: Disable operator-dictionary-spacing-004.html Operator dictionary chunk 1 - lspace/rspace on Android; r=bc

This test is mysteriously failing under a try push with e10s-multi enabled on
Android. Since MathML is not super-important to us, I'd like to disable it on
Android and file a follow-up bug in MathML for the failure.

Differential Revision: https://phabricator.services.mozilla.com/D94151

testing/web-platform/meta/mathml/presentation-markup/operators/operator-dictionary-spacing-004.html.ini

 [operator-dictionary-spacing-004.html]
   [Operator dictionary chunk 1 - lspace/rspace]
+    disabled:
+      if (os == "android"): https://bugzilla.mozilla.org/show_bug.cgi?id=1668892
     expected:
       if (os == "mac") and debug: ["PASS", "FAIL"]