Add support for Volume textures to have residency changed as regular textures

Source/Engine/Graphics/Textures/GPUTexture.cpp

@@ -813,5 +813,5 @@ void GPUTexture::SetResidentMipLevels(int32 count)
     if (_residentMipLevels == count || !IsRegularTexture())
         return;
     _residentMipLevels = count;
-    onResidentMipsChanged();
+    OnResidentMipsChanged();
 }

Source/Engine/Graphics/Textures/GPUTexture.h

@@ -567,12 +567,12 @@ public:
     /// Sets the number of resident mipmap levels in the texture (already uploaded to the GPU).
     /// </summary>
     API_PROPERTY() void SetResidentMipLevels(int32 count);
-
+    
 protected:
 
     virtual bool OnInit() = 0;
     uint64 calculateMemoryUsage() const;
-    virtual void onResidentMipsChanged() = 0;
+    virtual void OnResidentMipsChanged() = 0;
 
 public: