[LYN-3913] Fix conversion to unsupported photometric unit on light type change.

When converting to a light type that doesn't support the currently used photometric unit, the editor component will convert the photometric unit to the universally supported lumen.

Signed-off-by: Ken Pruiksma <pruiksma@amazon.com>

Gems/AtomLyIntegration/CommonFeatures/Code/Source/CoreLights/EditorAreaLightComponent.cpp

@@ -264,6 +264,22 @@ namespace AZ
             // Update the cached light type.
             m_lightType = m_controller.m_configuration.m_lightType;
             
+            // Check to see if the current photometric type is supported by the light type. If not, convert to lumens before deactivating.
+            auto supportedPhotometricUnits = m_controller.m_configuration.GetValidPhotometricUnits();
+            auto foundIt = AZStd::find_if(
+                supportedPhotometricUnits.begin(),
+                supportedPhotometricUnits.end(),
+                [&](const Edit::EnumConstant<PhotometricUnit>& entry) -> bool
+                {
+                    return AZStd::RemoveEnum<PhotometricUnit>::type(m_controller.m_configuration.m_intensityMode) == entry.m_value;
+                }
+            );
+
+            if (foundIt == supportedPhotometricUnits.end())
+            {
+                m_controller.ConvertToIntensityMode(PhotometricUnit::Lumen);
+            }
+            
             // componets may be removed or added here, so deactivate now and reactivate the entity when everything is done shifting around.
             GetEntity()->Deactivate();
 
@@ -334,6 +350,11 @@ namespace AZ
                 break;
             }
 
+            if (foundIt == supportedPhotometricUnits.end())
+            {
+                m_controller.ConvertToIntensityMode(PhotometricUnit::Lumen);
+            }
+
             return true;
         }