Allow piping VM failure reason

Allow crosvm to write a VM failure reason to virtualizationservice via the pipe provided.

Fixes this denial: avc: denied { write } for path="pipe:[95872]"
dev="pipefs" ino=95872 scontext=u:r:crosvm:s0
tcontext=u:r:virtualizationservice:s0 tclass=fifo_file

Bug: 220071963
Test: Run VM, no denial.
Change-Id: I3beedc5e715aa33209d3df0cae05f45f31e79e66
1 file changed