Unable to configure settings in provideRemoteConfig

### Version info

**Angular:**
^12.2.9

**Firebase:**
^9.1.2

**AngularFire:**
^7.1.0

**Other (e.g. Ionic/Cordova, Node, browser, operating system):**

"rxfire": "^6.0.2",
"rxjs": "^6.6.7",

Node LTS (14)
npm@6

### How to reproduce these conditions

**Failing test unit, Stackblitz demonstrating the problem**

**Steps to set up and reproduce**

Copy the following code in the `imports` modules of `AppModule`:

```ts
provideFirebaseApp(() => initializeApp(environment.firebase)),
provideAuth(() => getAuth()),
provideMessaging(() => getMessaging()),
provideAnalytics(() => getAnalytics()),
provideRemoteConfig(() => {
console.log('provideRemoteConfig')
const remoteConfig = getRemoteConfig();

if (isDevMode()) {
console.log('isDevMode')
remoteConfig.settings.minimumFetchIntervalMillis = 10 * 1000;
}

return remoteConfig;
}),
```

### Expected behavior

It should run the code (console.log, etc...) and set the fetch time in dev env.

### Actual behavior

Currently, it does nothing (no console output) and it's really hard to work with Remote Config since it's 12 hours throttle update with default settings...

Reproduce the issue with the AppModule snippet and trace the provideRemoteConfig entry point alongside the other provider functions. Verify why the callback does not log or apply minimumFetchIntervalMillis, then confirm that the callback runs and the development fetch interval is applied.

Written by the indexing model from the issue text.