Match cache size between puffdiff and lz4diff am: ea4ca42744

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2850109

Change-Id: I8d50b88ed08d1c3f1301ca72bc882939db56951d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>