Fix generate_hiddenapi_lists_test.py am: 2019bc53c2 am: f74d4b8da7 am: c22ef81485

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1580530

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I2a6b9d22d3752ed21e92f975921a8dea9f233d31