Hide injected_file related quotas for V3 API

The injected_files, injected_file_content_bytes and
injected_file_path_bytes are all related to the
os-personalities extension which has been removed. They
can't be removed from the core quotas code as that has
to still support the V2 API. So for the V3 API we just
hide them.

DocImpact

Partially implements blueprint v3-api-remove-extensions

Change-Id: Iedb6e1427ac22f1926e929f3391e56403c37d088
Merge "Hide injected_file related quotas for V3 API"