This fixes a variety of small bugs in layer handling and adds a new API
for acquiring privileges for the whole process.
Fixes#22404 (but only for new images -- existing images will need to be
re-pushed).
Signed-off-by: John Starks <jostarks@microsoft.com>
Upstream-commit: 6d40104f116abdf9740c60846320ce6d36f03edd
Component: engine