Tests to verify new ParcelFileDescriptor events.

ParcelFileDescriptor now offers richer details around remote closure,
including detection of success, error, or crash.

To verify behavior, create two isolated processes which can construct
and trade PFDs with one another, and be instrumented to perform
various operations on those PFDs.  Tests to verify pipe, socket, and
normal file behavior under success, error, and crashes.

Bug: 10330121
Change-Id: Ibeff830c0d242c37eae12e5c8916575fa8a46d51