Accessing Firestore through reverse proxy

[lihyin]

We need to identify all network traffic that a specific Android/iOS app induces. The app is using Firestore in the backend. By default, connections to Firestore always use the domain firestore.googleapis.com instead of a project-specific subdomain (like Cloud Functions do, for example). This way those connections can't be related to a specific app by only examining the outgoing or incoming network traffic of the device.

Is it possible to route the traffic through a proxy or similar to be able to identify connections uniquely?

+-----+ +---------------+ +----------------------------+
| App | ----> | Reverse Proxy | ----> | Firestore |
| | <---- | (mydomain.com)| <---- | (firestore.googleapis.com) |
+-----+ ^ +---------------+ +----------------------------+
|
|

Is this possible with Firestore (at least, there's a function setHost() or Settings(httpClient: httpProxyClient) in the client SDK)?