$npm_package_version no longer works?

Hi there.

We have a number of Amplify apps and all of them set an environment variable called "REACT_APP_VERSION" to "$npm_package_version"

In all our previous apps, it works as intended in our code:

````
Version {process.env.REACT_APP_VERSION}
````

produces "Version 1.0.1" (or whatever)

However, on a newly deployed app, we're getting

"Version $npm_package_version"

Start by reproducing the reported deployment with REACT_APP_VERSION set to "$npm_package_version" and compare it with the earlier applications described in the report. Trace how Amplify Hosting passes environment variables into the React build; done means determining whether the package version should be expanded or documenting the supported configuration and resulting behavior.

Written by the indexing model from the issue text.