releasetools: Remove '-w' from ota_from_target_files options.

'-w' is a short option for '--wipe_user_data', which happens to be the
same as the whole-file signing flag for signapk.

This CL removes the short version to make it less error-prone. Users
should use '--wipe_user_data' to generate packages with enforced data
wipe.

Bug: 70259309
Test: ota_from_target_files.py generates packages with and without
      '--wipe_user_data'.
Test: Not seeing active users that uses 'ota_from_target_files -w'.
Change-Id: Ib8c138663a87aafc6a0b5b6f7c286fb74ef6134b