Add bz2 and elementtree modules. am: 57d51f2bf6 am: 991af89d2c am: 2cba696386 am: f18e3d8345

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

Change-Id: Ifa49c5a7f6fd976e5ce2bfc1f0c712329342e284
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>