If we're not delegating then we change _connection into a local
connection midway through the file but we don't change
_play_context.connection (no need to alter that). When we later check
it in process_remote() we need to know the actual connection, not the
connection that we thought we were going to use at the start of run().
So we have to use _connection.transport in process_remote(). The rest
of the places could use either one (because we have not yet changed to
a local connection) but we go ahead and switch those to
_connection.transport as well to avoid confusion in the future.
Fixes https://github.com/ansible/ansible-modules-core/issues/3136