Allow apk path to contain one subdirectory.

In the current directory layout this prevented rm_dex and move_dex
commands to validate the apk path and thus cleaning up resources.

Bug: 16888084

(cherry picked from commit fd88ff2edd954117e36372fb095b6f5f35aad0e3)

Change-Id: I1002529b0c35852c67540d3165d1444523460592
Merge "Allow apk path to contain one subdirectory." into du44