[fenix] For https://github.com/mozilla-mobile/fenix/issues/975: Removes leakcanary and default browser telemetry (https://github.com/mozilla-mobile/fenix/pull/3350)

app/metrics.yaml

@@ -141,9 +141,8 @@ events:
       A user toggled a preference switch in settings
     extra_keys:
       preference_key:
-        description: "The preference key for the switch preference the user toggled. We currently track: leakcanary,
+        description: "The preference key for the switch preference the user toggled. We currently track:
-          make_default_browser, show_search_suggestions, show_visited_sites_bookmarks, remote_debugging, telemetry,
+          show_search_suggestions, show_visited_sites_bookmarks, remote_debugging, telemetry, tracking_protection"
-          tracking_protection"
       enabled:
         description: "Whether or not the preference is *now* enabled"
     bugs:

app/src/main/java/org/mozilla/fenix/components/metrics/Metrics.kt

@@ -94,8 +94,6 @@ sealed class Event {
 
     data class PreferenceToggled(val preferenceKey: String, val enabled: Boolean, val context: Context) : Event() {
         private val switchPreferenceTelemetryAllowList = listOf(
-            context.getString(R.string.pref_key_leakcanary),
-            context.getString(R.string.pref_key_make_default_browser),
             context.getString(R.string.pref_key_show_search_suggestions),
             context.getString(R.string.pref_key_show_visited_sites_bookmarks),
             context.getString(R.string.pref_key_remote_debugging),