DO NOT MERGE Monotonic flag sets incorrectly in rangelib

After applying update_target_files_incr_ext4.sh, some files may end up
occupying unsorted block fragments. In one example, an apk file has the
block range [258768-259211,196604]. The monotonic flag in rangelib sets
incorrectly for this example and leads to a bad input file for imgdiff.
After fixing the flag, bsdiff is called instead of imgdiff and the
incremental OTA package generates successfully.

Bug: 28760775
Bug: 28053885
Change-Id: Ib841bf449ff6a29314fc4a1b8fba941a6dc532ac
(cherry picked from commit cd1e16a7)