FR: Add Download Size for Android MLKit translation models

[AndrewLauder]

Feature proposal

• Firebase Component: MLKit/Translate

Add size to MLKit download. Adding size would allow developers to build a better user experience by showing the user how much data will be used.

[ashwinraghav]

Thanks for reaching out. Is you proposal to have this be programmatically available before a download starts?

[AndrewLauder]

Thanks for reaching out. Is you proposal to have this be programmatically available before a download starts?

Yes, so we can display to the user the size of the download.

[gzqyl]

why not offer the model separately? At some scene, we may need the model directly that bundled with app, as download is not suitable for everyone