appsdk-bump-app-catalog 680 bumping sdk to 2306-897851a

sdk commit: RallySoftware/appsdk@d207cffda0f0460c52f1a60003420d4b83c160df
author: Matt Parrish and Kevin Roberts
message: Fixing drag handle column image on flat grid. It was a styling issue.

sdk commit: RallySoftware/appsdk@897851a17eefa0815e69a9d59a3ba5e2e81ef1eb
author: Kyle Morse and Alan Brockett
message: Final 2.0rc3 doc tweaks