Prevent update/delete of managed records in v1 API

This is a partial fix, as the V2 API may still update/delete these
records. As the V2 API is still experimental, I'd like to fix the V1
API first - and ensure the "managed=True" flag is set correctly ASAP.

Closes-Bug: 1373913
Change-Id: If1de4c0043cf735e1f5e32ee1a1c0996d0a0ab8e
Merge "Prevent update/delete of managed records in v1 API"