Amend comments on mark_flag_as_required and mark_flags_as_required so they do not encourage dual use of modules as both directly executable and importable.
Amend comments on mark_flag_as_required and mark_flags_as_required so they do not encourage dual use of modules as both directly executable and importable.

PiperOrigin-RevId: 328193869
Change-Id: I4fa1d43c6e226b1239bd8bc66900c99cf5ce6abe

abseil/abseil-py,abseil/abseil-py