When the daemon process or the host running it is abruptly terminated,
the layer metadata file can become inconsistent on the file system.
Specifically, `link` and `lower` files may exist but be empty, leading
to overlay mounting errors during layer extraction, such as:
"failed to register layer: error creating overlay mount to <path>:
too many levels of symbolic links."
This commit introduces the use of `AtomicWriteFile` to ensure that the
layer metadata files contain correct data when they exist on the file system.
Signed-off-by: Mike <mike.sul@foundries.io>
de2447c2ab