Again, I'm not sure if you want an explanation here, or in the wrapper.

The impetus for this change was that I could figure out why a project wouldn't compile correctly from the command line.  It turned out that these wrapper scripts were hard coding build-tools version 17.0.0 as the executed version.  I wanted to update the default, and provide a way to override the version executed in case a user discovers incompatibilities compiling their project with a certain version of build-tools.