Clarify licensing -- GPL does not apply am: e754edc259

Original change: https://android-review.googlesource.com/c/platform/external/python/cpython3/+/2254806

Change-Id: I6a8fd36256bd94d0147c9813231aafa014a30413
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>