Changing paths to Gradle dependencies are included in build

To use the downloaded Gradle dependencies for our Android Tor Browser we do

  export GRADLE_MAVEN_REPOSITORIES="file://$rootdir/[% c('input_files_by_name/gradle-dependencies') %]"

$rootdir, however, results in including a changing path into the final .apk as it gets embedded into chrome/toolkit/content/global/buildconfig.html. The result is something like "file:///var/tmp/tmp.Flce6AvlTV/gradle-dependencies-3" which breaks our reproducible builds.