Bug 1584352 - Use sinon matcher instead of exact call list in Normandy addon rollout test r=Gijs

This avoids an intermittent test failure when other parts of Firefox set
experiments active while this test is running.

Differential Revision: https://phabricator.services.mozilla.com/D47947

--HG--
extra : moz-landing-system : lando

toolkit/components/normandy/test/browser/browser_actions_AddonRolloutAction.js

@@ -74,9 +74,10 @@ decorate_task(
     sendEventStub.assertEvents([
       ["enroll", "addon_rollout", recipe.arguments.slug],
     ]);
-    Assert.deepEqual(
-      setExperimentActiveStub.args,
-      [["test-rollout", "active", { type: "normandy-addonrollout" }]],
+    ok(
+      setExperimentActiveStub.calledWithExactly("test-rollout", "active", {
+        type: "normandy-addonrollout",
+      }),
       "a telemetry experiment should be activated"
     );