libprocessgroup users use libcutils

libprocessgroup symbols are being moved into libcutils in order to
optimize linking/memory usage. libprocessgroup will no longer be
required in the future (however removing references to it will come
separately).

Since libcutils is used statically here, the dependencies of
libprocessgroup need to be explicitly listed.

Bug: 135145426
Test: boot
Change-Id: I91c082f0fa2f5f5c52751065cd5f50f5cb965b23