Cryptomatte not readable in nuke (arnold 7.2.4.0)

[cpichard]

Describe the bug
In the last release 7.2.4.0 the cryptomatte images generated by husk are correctly read by houdini but not by nuke. This has been introduced in #1697

Used Software Versions

• Arnold: 7.2.4.0
• USD: 22.11

[autodesk-oss-arnold-bot]

Issue synced internally to ARNOLD-14249

[autodesk-oss-arnold-bot]

Issue synced internally to ARNOLD-14274