Yet More Datadog Setup

[annamontare-nava]

JIRA Ticket:
BB2-XXXX

What Does This PR Do?

Yet more setup of Datadog monitors and dashboards.

• warn on no data for RDS in sandbox and prod
• switch to fips-complaint Datadog agent container

This PR will require a tofu apply during deployment.

What Should Reviewers Watch For?

If you're reviewing this PR, please check for these things in particular:

Validation

What Security Implications Does This PR Have?

Please indicate if this PR does any of the following:

• Adds any new software dependencies
• Modifies any security controls
• Adds new transmission or storage of data
• Any other changes that could possibly affect security?

• Yes, one or more of the above security implications apply. This PR must not be merged without the ISSO or team
  security engineer's approval.

Any Migrations?

• Yes, there are migrations
  • The migrations should be run PRIOR to the code being deployed
  • The migrations should be run AFTER the code is deployed
  • There is a more complicated migration plan (downtime,
    etc)
• No migrations