Print memory usage info when grootfs init-store fails
Print memory usage info when grootfs init-store fails

We have observed some flakes caused by grootfs init-store failing, and
some research suggests it could be related to the amount of free memory
in the system.

Co-authored-by: Georgi Sabev <cd7643e50243a10153b49cb72b4bdbf8b48cb045@gmail.com>

cloudfoundry-incubator/guardian,cloudfoundry-incubator/guardian,cloudfoundry-incubator/guardian