Avoid more sources of camera update re-entrancy that can lead to stack overflow (#1136)

Code/Sandbox/Editor/EditorViewportWidget.cpp

@@ -2887,9 +2887,12 @@ void EditorViewportWidget::UpdateCameraFromViewportContext()
     AZ::Matrix3x4 matrix;
     matrix.SetBasisAndTranslation(cameraState.m_side, cameraState.m_forward, cameraState.m_up, cameraState.m_position);
     auto m = AZMatrix3x4ToLYMatrix3x4(matrix);
+
+    m_updatingCameraPosition = true;
     SetViewTM(m);
     SetFOV(cameraState.m_fovOrZoom);
     m_Camera.SetZRange(cameraState.m_nearClip, cameraState.m_farClip);
+    m_updatingCameraPosition = false;
 }
 
 void EditorViewportWidget::SetAsActiveViewport()

Gems/Camera/Code/Source/CameraComponentController.cpp

@@ -387,6 +387,11 @@ namespace Camera
 
     void CameraComponentController::OnTransformChanged([[maybe_unused]] const AZ::Transform& local, const AZ::Transform& world)
     {
+        if (m_updatingTransformFromEntity)
+        {
+            return;
+        }
+
         if (m_view)
         {
             CCamera& camera = m_view->GetCamera();