rootdir: Add cgroups and task profiles description files

Add cgroups.json and task_profiles.json file to be places under /etc/ on
the device to describe cgroups to be mounted and task profiles that
processes can request. This adds additional layer of abstraction between
what a process wants to achieve and how system implements that request.

Bug: 111307099
test: builds, boots

Change-Id: If92f011230ef5d24750e184bad776f30ba226f86
Merged-In: If92f011230ef5d24750e184bad776f30ba226f86
Signed-off-by: Suren Baghdasaryan <surenb@google.com>