Add missing code for recording Google Photos launches from the launcher

Previously we weren't actually recording launches of Google Photos as we
were for other apps.

Change-Id: I39deebdf470d91cc787936d15b2f90e18303cd33
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2434123Reviewed-by: dstockwell <dstockwell@google.com>
Reviewed-by: Nancy Wang <nancylingwang@chromium.org>
Commit-Queue: Raymes Khoury <raymes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811159}

chrome/browser/apps/app_service/app_service_metrics.cc

@@ -222,6 +222,8 @@ void RecordAppLaunch(const std::string& app_id,
   else if (app_id == extension_misc::kGoogleKeepAppId)
     RecordDefaultAppLaunch(DefaultAppName::kKeep, launch_source);
 #if defined(OS_CHROMEOS)
+  else if (app_id == extension_misc::kGooglePhotosAppId)
+    RecordDefaultAppLaunch(DefaultAppName::kPhotos, launch_source);
   else if (app_id == arc::kPlayBooksAppId)
     RecordDefaultAppLaunch(DefaultAppName::kPlayBooks, launch_source);
   else if (app_id == arc::kPlayGamesAppId)