We have a couple of active imgdiff workarounds (and likely with one more
inbounding that allows having shared blocks in ext4 image). Most of
these workarounds need extending imgdiff's capability. While us not
getting there anytime soon, collect the stats to better understand the
impact of each kind so we can prioritize accordingly.
A sample report is as follows.
Imgdiff Stats Report
========================
APK files diff'd with imgdiff (count: 88)
-------------------------------------------
/system/priv-app/Shell/Shell.apk
...
Large APK files split and diff'd with imgdiff (count: 4)
----------------------------------------------------------
/system/priv-app/Settings/Settings.apk
...
Bug: 68016761
Test: Generate an incremental BBOTA package. Check the stats report.
Test: python -m unittest test_blockimgdiff
Change-Id: I27ad862cde472ab2806db877632ce5a0607420f2
294651d7b4