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

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

Change-Id: Iae9d2cc31c3d65048b051dbae9be99bc1e4a00ca
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>