Non-descriptive error message when a BOSH job spec property name is a prefix for another one

Describe the bug
It seems that BOSH Director has the following requirement for the properties in a spec file:
No property name should be a prefix for the name of another one.
The problem is that the error message ("string not matched") is inadequate and does not point to the cause of the error.

To Reproduce
Steps to reproduce the behavior (example):
Using the bosh CLI, deploy a job with a spec file that contains something like:

properties:
  ala:
    <...>
  ala.bala:
    <...>

Expected behavior
A clear and concise description of what the problem is (e.g.: The property name "ala" is a prefix for the property name "ala.bala" and this is not allowed.).

Logs
The Ruby exception from the BOSH Director's debug logs is attached.

Versions (please complete the following information):

• Infrastructure: AWS, GCP, Azure
• BOSH version: 280.0.15
• BOSH CLI version: 7.5.0
• Stemcell version: ubuntu-jammy 22.04.1/1.351

Start by reproducing the failure with a BOSH job spec containing both "ala" and "ala.bala", then inspect the attached Ruby exception in the BOSH Director debug logs. Trace the property-name validation that produces "string not matched". Done means the Director reports which property is a prefix of the other, with coverage for this example.