Add bz2 and elementtree modules. am: 57d51f2bf6 am: 991af89d2c am: 2cba696386

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

Change-Id: Id9b65a137c15fb980731027aace2a63bd350011f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>