optional policy assignment module in root deployment

[glennmusa]

Description

Adds a deployPolicy boolean that defaults to false to the root deployment to conditionally deploy policyAssignment modules to hub and spoke resource groups.

To demo this without policy:

az deployment sub create \
  --name withoutPolicy \
  --location eastus \
  --template-file mlz.bicep

To demo this with policy:

az deployment sub create \
  --name withPolicy \
  --location eastus \
  --template-file mlz.bicep \
  --parameters deployPolicy=true \
  --parameters policy=NIST

Issue reference

The issue this PR will close: #489

Checklist

Please make sure you've completed the relevant tasks for this PR out of the following list:

• All acceptance criteria in the backlog item are met
• The documentation is updated to cover any new or changed features
• Manual tests have passed
• Relevant issues are linked to this PR

[jjansen23]

@glennmusa - Deploying the branch in commercial and saw a Warning:
"missionlz/src/bicep> az deployment sub create --name withoutPolicy --location eastus --template-file mlz.bicep
A new Bicep release is available: v0.4.1008. Upgrade now by running "az bicep upgrade".
/home/jerome/missionlz/src/bicep/modules/securityCenter.bicep(73,34) : Warning BCP081: Resource type "Microsoft.Security/policies@2015-06-01-preview" does not have types available.
"
It still deployed successfully . Any concerns ?

[glennmusa]

@glennmusa - Deploying the branch in commercial and saw a Warning: "missionlz/src/bicep> az deployment sub create --name withoutPolicy --location eastus --template-file mlz.bicep A new Bicep release is available: v0.4.1008. Upgrade now by running "az bicep upgrade". /home/jerome/missionlz/src/bicep/modules/securityCenter.bicep(73,34) : Warning BCP081: Resource type "Microsoft.Security/policies@2015-06-01-preview" does not have types available. " It still deployed successfully . Any concerns ?

Nope! No concerns w/r/t optionally deploying policy. That's a warning from changes unrelated to these.

There's already an issue out to remediate this warning, but it should not affect a deployment: #485