Inserting existing key with invalid doc_size returns 'ValueTooLargeException'

Build: 7.0.0-1569

Scenario:

1. Two node cluster, Couchbase bucket(replica=1)
2. Insert key 'test-doc-0' with valid doc_size (Insert succeeds)
3. Insert same key with invalid doc_size (21MB)

Observation:

Step#3 results in 'ValueTooLargeException'

Expected behavior:

Since the key is already existing in the server, we should get 'DocumentExistsException' irrespective of the value of the document.

Attaching doc_create.pcapngfor further debugging.