Run ZipFile.testzip() during zipfile tests.
Run ZipFile.testzip() during zipfile tests.

This still doesn't catch the issue that [1] fixes, but it's probably a
good idea anyway.

[1]: https://android-review.googlesource.com/#/c/143469/

Change-Id: Iaa607ec7450d605b26114bd81ea41a14c6613c0e

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build