title: Where is a good AOSP Makefile to put PRODUCT_PACKAGES+=mytool
body: <p>I'm working with an internal tool for a few users building in AOSP tree.
  To enable the build of this tool it must be added to <code>PRODUCT_PACKAGES</code> variable somewhere in the make-system.</p>
  
  <pre><code>PRODUCT_PACKAGES+=mytool
  </code></pre>
  
  <p>Upto now I have maintained this as uncommitted changes to <code>/build/make/target/product/base_system.mk</code> I could of course fork this module and maintain my patch or maintain it as a diff and patch it when a new workspace is created.</p>
  
  <p>The project now needs to be shared with a handful of coworkers, so this is a good opportunity to make it less hacky and more maintainable as a forked module requires constant merges of upstream patches.</p>
  
  <p>The project only maintain one git repo for manifest and one for the tool itself.</p>
  
  <p>How could I add this assignment of to a Makefile without having to maintain it as a shell script or a forked version of one of the android gits?</p>