Kleaf: init_ddk: Add initial unit testing

* This changes adds testing for:
  * Directory creation correctly handled.
  * Correct symlink of tools/bazel.
  * Prebuilts setup for both relative to workspace or not.

* Little cleanup of the now obsolete create_directory class method.

Bug: 328770706
Change-Id: Ic4d5c43128f1b9a5919fc7ace1d8abd13fccb48d
Signed-off-by: Ulises Mendez Martinez <umendez@google.com>
2 files changed