Move py-jinja to src folder am: fec0515194 am: 6e27281228 am: 8d6e25a8af

Original change: https://android-review.googlesource.com/c/platform/external/python/jinja/+/2215007

Change-Id: Id4b948a5696d9449aa65f101724a1f7ad57b3b00
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>