firebase-tools emulators fails silently when firebase client code is initialized with a different project config

### [REQUIRED] Environment info

**firebase-tools:** @8.16.2

**Platform:** Windows 10

### [REQUIRED] Test case

I've described the best I could. I hope it helps to improve the package.

### [REQUIRED] Steps to reproduce

I was getting strange behaviors from firebase Firestore emulator. It seems that the problem was that `firebase-tools` had a different selected project as from the project that was being initialized by my client code with: `firebase.initializeApp(config);`.

What I mean is:

`firebase.initializeApp(config)` was pointing to a `.env` file that had the config for a `project-old` keys.

**.env**

```
FIREBASE_APP_API_KEY="OLD_KEY"
FIREBASE_APP_AUTH_DOMAIN="project-old.firebaseapp.com"
FIREBASE_APP_DATABASE_URL="https://project-old.firebaseio.com"
FIREBASE_APP_PROJECT_ID="project-old"
FIREBASE_APP_STORAGE_BUCKET="project-old.appspot.com"
FIREBASE_APP_MESSAGING_SENDER_ID="OLD_ID"
FIREBASE_APP_ID="OLD_ID"
```

And `firebase-tools` was set to: `project-new`. So, when I ran `firebase projects:list`, this is what I was getting:


### [REQUIRED] Expected behavior

I was expecting to get some warning about that difference between projects.

### [REQUIRED] Actual behavior

My client code was able to read data from Firestore emulator. But **only the initial data**. The one that was initialized with the emulator. It was unable to read any new data from the Firestore. For example: I would go to the emulators UI on `localhost:4000` and update some data. Even after refreshing my app, the app would still read the `initialData` and not the updated data. Also, no real time `onSnapshot` listeners were activated.

Ideally, I think that `firebase-tools` should be aware that its emulator is being called by a different firebase app, that was initialized on another project, and would show some kind of warning or error.

I feel that the emulator was failing silently and it was hard to find out what was wrong. No warnings or errors were being shown.

When I updated my client code to `initializeApp(config)` to the `project-new` keys, everything started to work fine again.

This is how I'm initializing the emulators:

```
firebase emulators:start --import=./src/firebase/emulatorData
```

This will initialize the emulators with the data from `./src/firebase/emulatorData`

And on my client code I have:

**firebase.ts**

```
firebase.initializeApp(config);

if (DEVELOPMENT) {
console.log(">>> From firebase.ts: activating emulators...");
firebase.functions().useFunctionsEmulator("http://localhost:5001");
firebase.firestore().settings({
host: "localhost:8080",
ssl: false
});
}
```

Start by reproducing the mismatch between the project in firebase.ts and the project selected by firebase emulators:start --import=./src/firebase/emulatorData. Trace how the emulator handles client connections and determine where a project mismatch could be detected; done means a clear warning or error is shown instead of silent stale reads and missing onSnapshot updates.

Written by the indexing model from the issue text.