Bug 1578579 - Add telemetry for privacy info in discovery stream r=gvn

Add two more event values to the Events telemetry

Differential Revision: https://phabricator.services.mozilla.com/D48352

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

toolkit/components/telemetry/Events.yaml

@@ -10,6 +10,7 @@ activity_stream:
       "BOOKMARK_ADD",
       "BOOKMARK_DELETE",
       "CLICK",
+      "CLICK_PRIVACY_INFO",
       "CLOSE_NEWTAB_PREFS",
       "DELETE",
       "DELETE_FROM_POCKET",
@@ -31,6 +32,7 @@ activity_stream:
       "SEARCH_EDIT_CLOSE",
       "SEARCH_EDIT_DELETE",
       "SEARCH_HANDOFF",
+      "SHOW_PRIVACY_INFO",
       "SKIPPED_SIGNIN",
       "SUBMIT_EMAIL",
       "DISCLAIMER_ACKED",