Remove unused libprocessgroup dependency am: 2dc99691ff

Original change: https://android-review.googlesource.com/c/platform/system/libhidl/+/3455940

Change-Id: Ie8b7db0ba84a6829be71d4d1c44281e7d7021a24
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>