openharmony/files: add missing files for Acts AmsZipfileUnzipfiletest

ceshi.txt and ceshitwo.txt are random text files needed to perform the
ActsAmsZipfileUnzipfileSTest,but were missing from the OpenHarmony
source tree.
They have been added to the 'files' directory, so that they can be used
by other recipes.

Signed-off-by: Kareem Zarka <kareem.zarka@huawei.com>