Merge "Allow extra_apex_payload_key to take multiple names at once"

      apkcerts.txt file, or the container key for an APEX. Option may be

      repeated to give multiple extra packages.

  --extra_apex_payload_key <name=key>

  --extra_apex_payload_key <name,name,...=key>

      Add a mapping for APEX package name to payload signing key, which will

      override the default payload signing key in apexkeys.txt. Note that the

      container key should be overridden via the `--extra_apks` flag above.

      for n in names:

        OPTIONS.extra_apks[n] = key

    elif o == "--extra_apex_payload_key":

      apex_name, key = a.split("=")

      OPTIONS.extra_apex_payload_keys[apex_name] = key

      apex_names, key = a.split("=")

      for name in apex_names:

        OPTIONS.extra_apex_payload_keys[name] = key

    elif o == "--skip_apks_with_path_prefix":

      # Check the prefix, which must be in all upper case.

      prefix = a.split('/')[0]