title: How to declare a constant that is visible to all modules' build.gradle file?
body: <p>I have a project that has multiple Modules - libraries and applications. Everytime a new version of Android comes out, I need to upgrade the targetSdk, compileSdk, buildToolsVersion, etc. for all the modules. A constant could help with this tedious work!</p>
  
  <p>How could I define project-level constant that is visible to all module's build.gradle?</p>