Update BeamLargeFiles/build.gradle to fix null output dir

The build.gradle file for BeamLargeFiles wasn't importing the
template engine dependencies, so it wasn't setting any of the
build variables that should've been set.

This was causing builds to get sent to a null directory, as well
as causing emitGradleZip to go into an infinite loop.

Change-Id: I640d67253003a450ed9b1e47243bc9ce08142b30