Support for setting a default disk_quota for newly pushed apps.
Merge branch 'default_disk_quota' of https://github.com/youngm/cloud_controller_ng into youngm-default_disk_quota

Conflicts:
	rubocop-todo.yml
	spec/unit/lib/cloud_controller/config_spec.rb
Merge branch 'youngm-default_disk_quota'

[#68597786]

Signed-off-by: Michael Fraenkel <fraenkel@us.ibm.com>