Merge "libprocessgroup: return false on failure" am: 64f953e2 am: b3e5d4ed...

Merge "libprocessgroup: return false on failure" am: 64f953e2 am: b3e5d4ed am: f3dcab61 am: b719cbe9

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2059547



Change-Id: I13620aa9edd1f4186891fac961008550e730e70f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>