The addon package validator reported the required manifest as
`matadata.yaml` in two of its error messages, telling addon authors
to fix a file that does not exist. The correct filename is
`metadata.yaml` (see the MetadataFileName constant and the sibling
error on the missing-manifest branch, which already spell it right).
Correct the two misspelled literals in validateAddonPackage and update
the matching assertions in TestCheckAddonPackageValid, which already
exercises the empty-name and empty-version branches.
Signed-off-by: Anas Khan <83116240+anxkhn@users.noreply.github.com>
39183d5ba3