Adding UiAccess enabled binary to the signing list

This is needed to allow the UiAccess enabled binary to work.  Otherwise the
binary will crash on launch which is an undesirable behavior.

BUG=617185

Review-Url: https://codereview.chromium.org/2349583002
Cr-Commit-Position: refs/heads/master@{#419211}

remoting/host/installer/win/parameters.json

@@ -18,6 +18,7 @@
     "remoting_native_messaging_host.exe",
     "remoting_start_host.exe",
     "remote_assistance_host.exe",
+    "remote_assistance_host_uiaccess.exe",
     "remote_security_key.exe"
   ],
   "source": "chromoting.wxs",