Add free short codes for Direct Carrier Billing in Google Play

We want to avoid to show warning for possible charges
when Google Play tries to identify the user with an SMS-MO
sent to a short code (free of charge).

Signed-off-by: Salvatore Baglieri <salvobaglieri@google.com>

Change-Id: I75b37073c664e5fbf688da25c1c3145082ac91eb