Assert ban on framework <-> vendor comms over VndBinder

This adds neverallow rules which enforce the prohibition on
communication between framework and vendor components over VendorBinder.
This prohibition is similar in spirit to the one for Binder
communications.

Most changes consist of adding neverallow rules, which do not affect
runtime behavior. The only change which does affect runtime behavior
is the change which takes away the right of servicemanager domain to
transfer Binder tokens to hwservicemanager and vndservicemanager. This
grant was there by accident (because it was overly broad) and is not
expected to be needed: servicemanager, hwservicemanager, and
vndservicemanager are not supposed to be communicating with each
other.

P. S. The new neverallow rules in app_neverallows.te are covered by
the new rules in domain.te. The rules were nevertheless added to
app_neverallows.te for consistency with other *Binder rules there.

Test: mmm system/sepolicy
Bug: 37663632
Change-Id: I7c2ae23924bf0f2fed3f1e3a8d4d603129286329