Bug 1411269 - Enable extended telemetry in local developer builds. r=chutten

This changes the Telemetry enabling logic so that extended telemetry
gets enabled when MOZILLA_OFFICIAL is not defined and the update
channel is "default", which is the case for local developer builds.

MozReview-Commit-ID: 19vlItyHsKp

--HG--
extra : rebase_source : 730568329e579e63fb58fa2516a126893c73e636

toolkit/components/telemetry/TelemetryController.jsm

@@ -626,8 +626,13 @@ var Impl = {
     if (IS_UNIFIED_TELEMETRY) {
       // Enable extended Telemetry on pre-release channels and disable it
       // on Release/ESR.
+      let prereleaseChannels = ["nightly", "aurora", "beta"];
+      if (!AppConstants.MOZILLA_OFFICIAL) {
+        // Turn extended telemetry for local developer builds.
+        prereleaseChannels.push("default");
+      }
       const isPrereleaseChannel =
-        ["nightly", "aurora", "beta"].includes(AppConstants.MOZ_UPDATE_CHANNEL);
+        prereleaseChannels.includes(AppConstants.MOZ_UPDATE_CHANNEL);
       Telemetry.canRecordBase = true;
       Telemetry.canRecordExtended = isPrereleaseChannel ||
         Services.prefs.getBoolPref(TelemetryUtils.Preferences.OverridePreRelease, false);