CBLT-202:  make sure new ANDR_DIR exists!

Change-Id: I8bb9fdb9fd12ef29bf4c54da5b0bb63bb1dcb485
Reviewed-on: http://review.couchbase.org/34498
Tested-by: Philip Labee <philip@couchbase.com>
Reviewed-by: Philip Labee <philip@couchbase.com>