Enhance the rpm validation workflow with certification validation

[zelinh]

Is your feature request related to a problem? Please describe

Enhance the rpm validation workflow with certification validation.
After we add rpm package signing, we will need certain validation for the signature after the distribution build workflow.

Describe the solution you'd like

Add the certification validation for rpm package when running rpm-validation workflow.

Describe alternatives you've considered

No response

Additional context

No response

[peterzhuamazon]

20220615:

• Add rockylinux8 systemd docker image for rpm signature checking on fips-enabled host #2198

[peterzhuamazon]

• Opensearch rpm validation fix: Remove leading agent setup to use stage agent setup #2199

[peterzhuamazon]

• Opensearch rpm validation fix2: Use yumdownloader for both yum and dnf and add yum import public key #2200
• Make sign artifact lib output clear msgs on utility versions #2201

[peterzhuamazon]

This issue has been resolved now.