Add post_update.sh am: 0e4ce3895a am: b6bfe838c5 am: 54727a26b0 am: 8ad94c0b8a am: 8b864e123c

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/protobuf-codegen/+/1443104

Change-Id: Id114567763d4b1c117ab5773c9a16fbe25cc69a3