Move py-jinja to src folder am: fec0515194

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

Change-Id: I95a86dfe7c487fa425688b1c1aa2c8904dace421
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>