Angular: Fix issue if BrowserAnimationsModule is imported

[valentinpalkovic]

Issue: N/A

If BrowserAnimationModule was used, the Story was not usable because BrowserModule is in place and using both modules in parallel is not allowed. Therefore we have to tell Angular while boostrapApplication to spin up an environment, where Animations are enabled.

What I did

How to test

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[shilman]

@valentinpalkovic This looks good, but can you please explain more about how to test it? If I tried your example on a previous SB7 beta, would it fail? Thanks in advance for the clarification!

[valentinpalkovic]

If you try to use the BrowserAnimationModule in the imports section of moduleMetadata, it will break in previous versions. For example here: https://github.com/storybookjs/storybook/pull/20709/files#diff-eab273740d3db246f7c17bb91c2f9750cb5b9de9fd4da6e8e2e238bc39d1591bR18

[valentinpalkovic]

@shilman Just copy over the Stories and the Dummy components and it should fail in previous betas.

[sheriffMoose]

Amazing work @valentinpalkovic , I just verified the changes on my end. Good catch 👍