fetch_souces.py: cache extracted hash and only extract if necessary
authorPyry Haulos <phaulos@google.com>
Wed, 10 Aug 2016 21:29:59 +0000 (21:29 +0000)
committerandroid-build-merger <android-build-merger@google.com>
Wed, 10 Aug 2016 21:29:59 +0000 (21:29 +0000)
am: 30e2e7b423

Change-Id: I8f1fab3874f5ba6168b014dc958597353b963af2


Trivial merge