Add network constraints for fetching notifications with WorkManager (#6305)

* Add `isNetworkBlocked` and `isInAirGappedEnvironment` to `NetworkMonitor`.

* Improve the DI of `SyncPendingNotificationsRequestBuilder` to simplify its usage.

* Only update `isInAirGappedEnvironment` in `DefaultNetworkManager` if the current build is an enterprise one.

* Add network constraints to `DefaultSyncPendingNotificationsRequestBuilder` based on the air-gapped status.

* Add a feature flag to disable the new check, in case it doesn't work as expected.

features/networkmonitor/api/src/main/kotlin/io/element/android/features/networkmonitor/api/NetworkMonitor.kt

@@ -24,5 +24,11 @@ interface NetworkMonitor {
     /**
      * Checks if the active network is being blocked by Doze, even if it's available.
      */
-    fun isNetworkBlocked(): Boolean
+    val isNetworkBlocked: StateFlow<Boolean>
+
+    /**
+     * A flow indicating whether the app is running in an air-gapped environment.
+     * An air-gapped environment is an environment that is not connected to the internet, and where the app can only communicate with a limited set of servers.
+     */
+    val isInAirGappedEnvironment: StateFlow<Boolean>
 }