Use a specific version of Bicep in the devcontainer and in automation

[glennmusa]

Benefit/Result/Outcome

So that developers that use the development container Dockerimage have consistent tooling and so that as releases are published the version of the tools that were used to develop the source are easily referenceable.

Description

Install a specific Bicep version in the development container.

Here's how it's done in the VSCode "try Bicep" container:

https://github.com/Azure/vscode-remote-try-bicep/blob/78d5170232c4a3db9f5a410346e57e0692162fdc/.devcontainer/Dockerfile#L22-L31

Acceptance Criteria

• Update the development container with the scripts necessary to install a specific version of Bicep
• When updating the development container Dockerfile, accept the Bicep version in a Dockerfile ARG so that it can be dynamically chosen, but defaulted to the team's choosing
• Update the validate-build-bicep.yml GitHub workflow to az bicep install --version ${bicep_version} and use the same version as described in the devcontainer