* Specify the ota zip name as the only parameter to extract-files.sh
* Will extract to $CM_ROOT/system_dump
* Bail out on A/B OTA zips. We cannot support these.
* Handles block based OTA zips by using sdat2img.py
* Store the zip's MD5 and check if its already extracted. If so, don't
bother extracting again
Change-Id: I03038e38dac51e6cb60d493c7e6362754d1daf02
