ATOM-16747 RPISystemInterface::GetDefaultScene returns the scene crea… (#5153)

* ATOM-16747 RPISystemInterface::GetDefaultScene returns the scene created by PreviewRenderer but not the Main Scene
Deprecate GetDefaultScene() function.
Update all the places which use GetDefaultScene to use Scene::GetFeatureProcessorFromEntityId or GetMainScene.
Tested with Editor, UI Editor, Material Editor, game launcher.

Signed-off-by: Qing Tao <55564570+VickyAtAZ@users.noreply.github.com>

Gems/AtomLyIntegration/CommonFeatures/Code/Source/Grid/GridComponentController.cpp

@@ -79,7 +79,7 @@ namespace AZ
             m_entityId = entityId;
             m_dirty = true;
 
-            RPI::ScenePtr scene = RPI::RPISystemInterface::Get()->GetDefaultScene();
+            RPI::Scene* scene = RPI::Scene::GetSceneForEntityId(m_entityId);
             if (scene)
             {
                 AZ::RPI::SceneNotificationBus::Handler::BusConnect(scene->GetId());