Improvements to measuring Bottlerocket settings to PCR 8

[ginglis13]

What I'd like:

Bottlerocket measures OS settings into PCR 8 via rottweiler. It currently excludes settings.network.hostname and settings.updates.seed:

https://github.com/bottlerocket-os/bottlerocket-core-kit/blob/b76210536e1f19f8922d1fa1854c43adae7a97bd/sources/rottweiler/src/system.rs#L164-L179

I would like more control over what OS settings are measured into PCR 8 with the ultimate goal of making PCR 8 predictions viable via pcrsys.

• Add settings.measurement.excluded-settings to variants with the encrypted-storage feature enabled
• Add optional PCR prediction to pcrsys when provided input user data TOMl

Any alternatives you've considered:

Keep the status quo