Flag Day for DC in build 164

If you don't use distro_const(1M) you can ignore this email.

If you are using build 164 or are in sync with slim_source gate my push for:

7001589 Implement a Transfer.create_checkpoint method

is flag day and manifests delivered must be used to build images.
This fix makes minor changes to DC manifests for all installers. Previously, "type" was an attribute for software_data and one needed to specify type="DIR" or type="FILE" when cpio was being used to transfer data. In the new manifests, "type" is associated with the tag software and DIR and FILE types are eliminated. "type" now is associated with types of transfer, such as CPIO, IPS, SVR4, P5I.