Add an explicit dependency on expected outputs list to grit rule

Prior to this CL removal of grit output file in BUILD.gn wasn't
triggering a re-run of grit if all other files are up-to-date. This may
cause a suprising output list verification failure later, during clean
build.

R=agrieve@chromium.org

Change-Id: I881992c174d5d3a2433759e2622929c4e84b3845
Reviewed-on: https://chromium-review.googlesource.com/c/1310274Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604620}

tools/grit/grit_rule.gni

@@ -329,6 +329,7 @@ template("grit") {
 
     inputs = [
       invoker.source,
+      asserted_list_file,
     ]
     if (resource_ids != "") {
       # The script depends on the ID file. Only add this dependency if the ID