With the "foreign" flag now stored in call_flags, restoring a call from
Redis restores this flag as well, overwriting the desired flag as we had
set it through call_get_or_create().
Reverse the flag setting by taking it out of call_get_or_create() (where
it's always false anyway, except when coming from Redis) and setting it
explicitly with call_make_own_foreign() after restorting call and its
flags.
Change-Id: Ib68be2aeedfa988b7555e426fa337657e1062245