Changes

mgw: Rearrange last steps of CRCX and MDCX

Make code in CRCX and MDCX look closer, since it is really doing the
same.
Move the dummy ping code after everything has been done correctly, since
the ping is just a side effect of the conn being created.

Change-Id: I42acda16cb2d59a9b7aae06b7584d4dfc1e91f9e