Mass app fixes for new API

Thanks @Willy-JL for finding issues and fixing many of those apps
Other apps fixed by me

mass_storage_app.c

@@ -22,15 +22,14 @@ static void mass_storage_app_tick_event_callback(void* context) {
 }
 
 void mass_storage_app_show_loading_popup(MassStorageApp* app, bool show) {
-    TaskHandle_t timer_task = xTaskGetHandle(configTIMER_SERVICE_TASK_NAME);
 
     if(show) {
         // Raise timer priority so that animations can play
-        vTaskPrioritySet(timer_task, configMAX_PRIORITIES - 1);
+        furi_timer_set_thread_priority(FuriTimerThreadPriorityElevated);
         view_dispatcher_switch_to_view(app->view_dispatcher, MassStorageAppViewLoading);
     } else {
         // Restore default timer priority
-        vTaskPrioritySet(timer_task, configTIMER_TASK_PRIORITY);
+        furi_timer_set_thread_priority(FuriTimerThreadPriorityNormal);
     }
 }