Remove system flag to use public_tenant for access consistency

[EvanCasey13]

Link(s) to Jira

https://issues.redhat.com/browse/RHCLOUD-30435

Description of Intent of Change(s)

Use public_tenant to access instead of system flag for consistency, replaced all filtering by public_tenant to use public_tenant_only() for consistency in public tenant filtering.

Local Testing

How can the feature be exercised?
How can the bug be exploited and fix confirmed?
Is any special local setup required?

Checklist

• if API spec changes are required, is the spec updated?
• are there any pre/post merge actions required? if so, document here.
• are theses changes covered by unit tests?
• if warranted, are documentation changes accounted for?
• does this require migration changes?
  • if yes, are they backwards compatible?
• is there known, direct impact to dependent teams/components?
  • if yes, how will this be handled?

Secure Coding Practices Checklist Link

• https://github.com/RedHatInsights/secure-coding-checklist

Secure Coding Practices Checklist

• Input Validation
• Output Encoding
• Authentication and Password Management
• Session Management
• Access Control
• Cryptographic Practices
• Error Handling and Logging
• Data Protection
• Communication Security
• System Configuration
• Database Security
• File Management
• Memory Management
• General Coding Practices

[astrozzc]

For the policies, the situation is different, we used system True to indicate the policies can not be updated, but the tenant is in each tenant. Maybe we can just ignore the system=True for policies. You might need to do some research if we have any system not true policies