All this is very inconvenient. Wouldn't it be simpler if you could specify in the layer that your file overrides the default? Well, you can do exactly that. Click that link, read, remove the impl dep, and then change the layer registration as follows:
<file name="WindowManager.wswmgr" url="WindowManager.wswmgr"><attr name="weight" intvalue="100"/>
Nice simplification, plus one less dependency in your application.