ITS: do not read stdin when spawning new process

Without sending STDIN to DEVNULL, parallel testing will stop test
processes unless using nohup. Changed behavior to send STDIN to DEVNULL.

Bug: 291095970
Test: tested locally
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:4456717bf0868f1f8ca0d93744ebec3d0d1b469f)
Merged-In: I1c2cc43cbeb45f9cc03c864e9747baefe7b0ecd9
Change-Id: I1c2cc43cbeb45f9cc03c864e9747baefe7b0ecd9
1 file changed