At the moment gradle.properties is checked in as an empty file. On my last (and first) pull request cketti mentioned better not to change gradle.properties because this may deviate from the AS build process. I don't understand that and want to discuss this:
-) As far as I can see, AS also uses gradle.properties. The only relevant setting is that it may use its own Gradle distribution to build a project. The recommended procedure should be to use the gradle wrapper.
-) It may be right that it is not a good idea to change gradle.properties because different users may have different needs but I am not sure if this is true here. It may be that it is necessary to have an eye on the things changed gradle.properties, but in my opinion there are at least some settings that should be valuable (and should be in there). For example, I have some memory settings in there to prevent from OutOfMemory. As the build may work on 32 bit systems, I doubt that the build will work on any 64-bit OS. Having such settings in there would make life easier for everyone starting with k-9. Other settings like org.gradle.parallel=true would also make sense.
What absolutely makes no sense in my opinion is to have an empty gradle.properties checked in. So either there are some useful settings in the file, or gradle.properties should be on the git ignore-list to prevent from unintentionally checking in the file.
br,
Wolfgang