Bug 1715223 - Override telemetry products check in test_DownloadList.js. r=mtigley

This test is now failing on Thunderbird, which doesn't have the telemetry events in question.

Differential Revision: https://phabricator.services.mozilla.com/D117130

toolkit/components/downloads/test/unit/test_DownloadList.js

@@ -15,6 +15,11 @@ const { TelemetryTestUtils } = ChromeUtils.import(
   "resource://testing-common/TelemetryTestUtils.jsm"
 );
 
+Services.prefs.setBoolPref(
+  "toolkit.telemetry.testing.overrideProductsCheck",
+  true
+);
+
 /**
  * Returns a Date in the past usable to add expirable visits.
  *