appsdk-bump-app-catalog 478 bumping sdk to 1970-975ddfd

sdk commit: RallySoftware/appsdk@07717ff216e113b44203326d44731190747ef5be
author: Steven Boles
message: S65212 Required custom fields in EDP now have a -- No Entry -- option

sdk commit: RallySoftware/appsdk@975ddfdf0a1f0a3c9c1776ce85d1b81fc5bb79c7
author: Matt Novinger, Dave Thompson and Eli Soman
message: Reapply "S64703: GridBoard shows grid by default."