libbinder: RPC avoid abort on too big allocations

We may want some more heuristic checks here, since allocations that are
just barely too big may interrupt the operations of other threads that
can't handle failing allocations, but this is a start so that too-big
allocations won't cause an abort.

Bug: 182938024
Test: binderRpcTest + running WIP fuzzer
Change-Id: Id9f1b63962cd22b7c799b14e595c47ea8628354f