Datastream already exists error instead of reusnig

[krishnamoorthy-r]

Expected Behavior

I expect the migration tool to reuse the stream if it already exists.

Actual Behavior

I get error "Already exists". I need to drop and create with new name everytime I need to retry because something failed.

Steps to Reproduce the Problem

1. Run spanner-migraiton-tool with more than once with the streamid populated in streaming.json file.

Specifications

• Version: latest
• Platform: unix