Index build stuck - Update index book-keeping on a KV snapshot rollback

a. Consider the following snapshot received by GSI: [snapStart-1, seqno-1, snapEnd-1]

b. Stream restart happened at this point

c. Indexer will request a stream with [snapStart-1, seqno-1, snapEnd-1]

d. Now, KV can send [snapStart-2, seqno-2, snapEnd-2]

KV only guarantees  snapEnd-2 > seqno-1

KV does not guarantee any ordering between snapEnd-1 and snapEnd-2. Indexer assumes snapEnd-2 >= snapEnd-1. If snapEnd-2 < snapEnd-1, indexer will ignore the new snapshot and this can lead to stream getting stuck for ever.