feat: support snapshots in Docker

[DimitarTachev]

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
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• All existing tests are passing: https://github.com/NativeScript/nativescript-dev-webpack/blob/master/CONTRIBUTING.md#testing-locally-by-running-e2e-tests
• Tests for the changes are included.

What is the current behavior?

We are not able to build snapshots on macOS Catalina.

What is the new behavior?

We are able to build snapshots on macOS Catalina using a Docker container.

Docker Image repository: https://github.com/NativeScript/docker-images/tree/master/

Related to: #1038