[macappsigner] Adjust plist's glob to read APFS packages
APFS pacakges, when extracted by 7zip don't have the root foobar.dmg directory (in contrast to HFS+ packages). So we should check two possible locations for the .plist file.
Fixes T17301
APFS pacakges, when extracted by 7zip don't have the root foobar.dmg directory (in contrast to HFS+ packages). So we should check two possible locations for the .plist file.
Fixes T17301