fix(kzgrs): Fix row commit hash to output 31 bytes

[kashepavadan]

1. What does this PR implement?

Solves issue #1749

2. Does the code have enough context to be clearly understood?

Yes, see issue

3. Who are the specification authors and who is accountable for this PR?

@megonen @danielSanchezQ @thomaslavaur

4. Is the specification accurate and complete?

Yes

5. Does the implementation introduce changes in the specification?

No, it aligns the code with the spec

Checklist

Warning

Do not merge the PR if any of the following is missing:

• 1. The PR title follows the Conventional Commits specification.
• 2. Description added.
• 3. Context and links to Specification document(s) added.
• 4. Main contact(s) (developers and specification authors) added
• 5. Implementation and Specification are 100% in sync including changes. This is critical.
• 6. Link PR to a specific milestone.

[danielSanchezQ]

Nice catch @kashepavadan !