Change r8_release to use gcert

prodaccess is now deprecated

Bug: 165214257
Change-Id: Ic5a499e130bfc410372d1eb9dc1a555a2ed75b47
diff --git a/tools/r8_release.py b/tools/r8_release.py
index 3641f0c..e813756 100755
--- a/tools/r8_release.py
+++ b/tools/r8_release.py
@@ -843,7 +843,7 @@
       or args.maven
       or (args.studio and not args.no_sync)
       or (args.desugar_library and not args.dry_run)):
-    utils.check_prodacces()
+    utils.check_gcert()
 
   if args.google3:
     targets_to_run.append(prepare_google3(args))