Update METADATA for 1.4.0. am: 8cc5fc4798 am: ed06f31303 am: 0257e5028a

Original change: https://android-review.googlesource.com/c/platform/external/python/absl-py/+/2871137

Change-Id: Ie15225813e043092f0184b04f6aaca7af655532c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>