[Feature request] GmsDocumentScanner API using InputImage like other MLKit libraries.

**What's your feature request? Please describe.**

Hi! I'm working on a new feature for our app. I need to allow the user to take a photo of a menu using the camera inside the app (not with an external Camera Intent), then scan this photo to extract the menu with corrected perspective, and then proceed to the next steps. I tried your GmsDocumentScanner library; it does this work perfectly but only with an external camera, which does not work for our app.
It would be great if you could provide an API similar to your other libraries (e.g., TextRecognition) with an input parameter like InputImage and returning Task or something similar.

**Mobile environment**

Android

**Additional context**

Android Developer at **Simple.Life Apps**
[https://play.google.com/store/apps/details?id=life.simple](https://play.google.com/store/apps/details?id=life.simple)