Add python symlink to python3 BUG=b:280640695 Change-Id: I0840abae09ae2798fdfb73bfd2d28bebffe5a440 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/xolabs-common-core/+/4500893 Reviewed-by: Prasad Vuppalapu <[email protected]> Commit-Queue: Anh Le <[email protected]> Tested-by: Anh Le <[email protected]>