In particular, don't ask the producer about error overrides when
it is still relying on the consumer to do its job first. This
needs to be policy for *any* transport-side error condition, not
just the one that was previously handled safely. Any transport-
initiated error "on the fly" means that the app-facing side of
the engine doesn't know to stop feeding data, and mustn't be
consulted with any blocking request.
We also now detect unexpected PACKAGE_REJECTED by the transport
after data streaming has begun, and translate that to the general
TRANSPORT_ERROR for correct handling down the line.
Bug 28399225
Bug 28375634
Change-Id: I613dc21bc9f2d23e6520eed6c3ac2e9dbc1d88dc
98f1ff0558