Add vendor cgroups and task_profiles support

Vendors should be able to specify additional cgroups and task profiles
without changing system files. Add support for /vendor/etc/cgroups.json
and /vendor/etc/task_profiles.json files which will augment cgroups and
task profiles specified in /etc/cgroups.json and /etc/task_profiles.json
system files.

Bug: 124960615
Change-Id: I548c2e866b65c19856a3617d75b75dcd06f7d5b7
Signed-off-by: Suren Baghdasaryan <surenb@google.com>