Add bz2 and elementtree modules. am: 57d51f2bf6

Original change: https://android-review.googlesource.com/c/platform/external/python/cpython3/+/2736473

Change-Id: I436b76a108f2ad1b8c5d9f9fce3d22ae19b73b2c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>