Merge "Add post_update script" into main am: e52385217d

Original change: https://android-review.googlesource.com/c/platform/external/expat/+/3443723

Change-Id: I17a7d8258761b9d86fcbac5e60bf5e4331ff6c51
Signed-off-by: Automerger Merge Worker <[email protected]>