Update Asset and Resource directory functionality to handle added directories via a "make" step so that generated files work

[silbinarywolf]

Why

getPath3/getPath4 calls are not meant to be made outside of Step.make function calls as the LazyPath might be generated/not exist yet. By changing the logic as written in PR #63, we can support generated directories.

We can also re-use the logic written for asset directories so that the resource directory is also appropriately handled / has the cache busted when you modify a file, such as examples/sdl2/android/res/values/strings.xml

Related issues and PRs

• Update Asset directory functionality to recursively search the directory and call apk.addFileInput for each file #63
• Update Asset directory functionality to recursively search the directory and call apk.addFileInput for each file #62