Sync: use the new SyncIndicator api

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/roomlist/RoomListService.kt

@@ -32,6 +32,11 @@ interface RoomListService {
         data object Terminated : State()
     }
 
+    sealed class SyncIndicator {
+        data object Show : SyncIndicator()
+        data object Hide : SyncIndicator()
+    }
+
     /**
      * returns a [RoomList] object of all rooms we want to display.
      * This will exclude some rooms like the invites, or spaces.
@@ -49,6 +54,11 @@ interface RoomListService {
      */
     fun updateAllRoomsVisibleRange(range: IntRange)
 
+    /**
+     * The sync indicator as a flow.
+     */
+    val syncIndicator: StateFlow<SyncIndicator>
+
     /**
      * The state of the service as a flow.
      */