[Android] Make sure all Ruby file paths are flattened into single Array

[darinwilson]

I was trying to integrate the motion_print gem into an Android app and got this error during the build:

rake aborted!
TypeError: no implicit conversion of Array into String
/Library/RubyMotion/lib/motion/project/template/android.rb:156:in `expand_path'
/Library/RubyMotion/lib/motion/project/template/android.rb:156:in `block (2 levels) in <top (required)>'
/Library/RubyMotion/lib/motion/project/template/android.rb:155:in `each'
/Library/RubyMotion/lib/motion/project/template/android.rb:155:in `block in <top (required)>'
Tasks: TOP => device => build

It looks like motion_print is exposing its file paths as an Array, and that doesn't get correctly flattened with the other file paths in the RubyMotion Android template. Since motion_print works fine in iOS, I'm assuming that this is a bug on the Android side.

Calling flatten on App.config.files does the trick, though I'm not sure if that's the best overall solution.

Here's a sample repo that illustrates the problem (along with a couple of other issues that I'll file as separate support requests): https://github.com/darinwilson/rma-testing/tree/master/gem_integration

[GantMan]

Great call! motion_print is a great gem and should be supported 👍