Verbatim PFB handover fails when using a common prefix

[nadove-ucsc]

This was observed when testing #6815 due to a situation like this:

Activity 65f821a0-c4c2-4f1b-83f1-292dfe24f719 is found in a primary bundle 1f47f146-6d32-adbd-bd87-93002479d031 (A) and also in a replica bundle (B). Its generated file (e47f0944-0bdb-422f-a251-3fab0c19a029) is also found in (A), and additionally in a separate replica bundle (C). Only (B) was indexed due to the use of common prefix 65/1. The resulting manifest contained a dangling reference to the generated file.

[edit @hannes-ucsc] … causing Terra to reject the manifest

[nadove-ucsc]

Here is an example of an import that failed for this reason