Update URL whitelist for externally_connectable

The Goodies page has moved, so need to update the manifest to match.
Also adding in URL pattern for staging location for Goodies webpages.

BUG=chromium:741952
TEST=browser test

Change-Id: Id1f71cb4bb6a65605a6ec6ff7cefd973a9487b35
Reviewed-on: https://chromium-review.googlesource.com/577724Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Commit-Queue: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488233}

chrome/browser/resources/chromeos/echo/manifest.json

@@ -40,7 +40,8 @@
   "externally_connectable": {
     "ids": ["*"],
     "matches": [
-      "*://www.google.com/*chrome/devices/goodies.html*"
+      "*://www.google.com/*chromebook/*",
+      "*://chromebook-dot-googwebreview.appspot.com/*chromebook/*"
     ]
   }
 }