Try increasing the cache index when re-creating the Flow<RootNavState>, otherwise sometimes we get a blank screen

Author: jmartinesp

appnav/src/main/kotlin/io/element/android/appnav/root/RootNavStateFlowFactory.kt

@@ -57,7 +57,7 @@ class RootNavStateFlowFactory(
      * @return a flow of integer, where each time a clear cache is done, we have a new incremented value.
      */
     private fun cacheIndexFlow(savedStateMap: SavedStateMap?): Flow<Int> {
-        val initialCacheIndex = savedStateMap.getCacheIndexOrDefault()
+        val initialCacheIndex = savedStateMap.getUpdatedCacheIndexOrDefault()
         return cacheService.clearedCacheEventFlow
             .onEach { sessionId ->
                 matrixSessionCache.remove(sessionId)
@@ -83,7 +83,7 @@ class RootNavStateFlowFactory(
         }
     }
 
-    private fun SavedStateMap?.getCacheIndexOrDefault(): Int {
-        return this?.get(SAVE_INSTANCE_KEY) as? Int ?: 0
+    private fun SavedStateMap?.getUpdatedCacheIndexOrDefault(): Int {
+        return (this?.get(SAVE_INSTANCE_KEY) as? Int)?.let { it + 1 } ?: 0
     }
 }