Added Bicep snippet for role assignment

[johnlokerse]

Added the res-role-assignment snippet.

Contributing a snippet

• I have a snippet that is either a single, generic resource or multi resource that uses parent-child syntax

• I have checked that there is not an equivalent snippet already submitted

• I have used camelCasing unless I have a justification to use another casing style

• I have placeholders values that correspond to their property names (e.g. dnsPrefix: 'dnsPrefix'), unless it's a property that MUST be changed or parameterized in order to deploy. In that case, I use 'REQUIRED' e.g. keyData

• I have my symbolic name as the first tab stop ($1) in the snippet. e.g. res-aks-cluster.bicep

• I have a resource name property equal to "name"

• If applicable, I have set the location property to location: /*${<id>:location}*/'location' (not resourceGroup().location) where <id> is a placeholder id, and added param location string to the test's main.bicep file so that the resulting main.combined.bicep file used in the tests compiles without errors

• I have verified that the snippet deploys correctly when used in the context of an actual bicep file

  e.g.

  resource aksCluster 'Microsoft.ContainerService/managedClusters@2021-03-01' = {
    name: 'name'

Question for the team

What is does the last item in the checklist mean? The tests ran without errors, but is there a way to test the snippet locally?

Microsoft Reviewers: Open in CodeFlow

[anthony-c-martin]

@johnlokerse - looks great, thank you for contributing! This should be included with the 0.7 Bicep release - ETA 10th June.