Revert "Fix python_binary_host module in mixed build."

Revert submission 1861755-fix_python_binary_host_in_mixed_build

Reason for revert: Broke Bazel CI, please see https://android-build.googleplex.com/builds/submitted/7879108/mixed_droid-clean/latest/view/logs/build_error.log and https://android-build.googleplex.com/builds/submitted/7879108/mixed_droid-incremental/latest/view/logs/build_error.log
Reverted Changes:
Ica457ee71:Add platform needed by python_binary_host.
Ibc8b99a92:Fix python_binary_host module in mixed build.

Change-Id: I3d6c4f6edee2d00bdc78efd5cee64f4c915baeaa