Add testcases for -t cd9660 -o isolevel=[1-3]

• -o isolevel=1 currently fails because of path comparison issues, so mark it as an expected failure.
• -o isolevel=3 is not implemented, so expect it to fail as an out of bounds value [*].

PR: 203645
MFC after: 1 week
X-MFC with: r290264
Sponsored by: EMC / Isilon Storage Division