[Fuchsia] Add cast_runner to restaged_packages.

Bug: 902138
Test: Builds locally.
Change-Id: If898f335dc9600d0de3996ecf45498bddb1322d9
Reviewed-on: https://chromium-review.googlesource.com/c/1321029
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605886}

webrunner/BUILD.gn

@@ -338,6 +338,7 @@ process_version("build_id") {
 # Puts copies of files at the top level of the CIPD archive's structure.
 copy("restaged_packages") {
   sources = [
+    "$root_gen_dir/webrunner/cast_runner/cast_runner.far",
     "$root_gen_dir/webrunner/chromium/chromium.far",
     "$root_gen_dir/webrunner/net_http/http/http.far",
     "$root_gen_dir/webrunner/web_runner/web_runner.far",
@@ -346,6 +347,7 @@ copy("restaged_packages") {
     "$_artifact_root/{{source_file_part}}",
   ]
   deps = [
+    ":castrunner_pkg",
     ":service_pkg",
     ":webrunner_pkg",
     "net_http:http_pkg",