[Plasma] Increase in index data size after recovery

Build : 5.5.0-2958 (GA build)

Steps:
1. Create a 2 node cluster - kv+index+query , kv+index
2. Create a default bucket
3. Use cbworkloadgen to populate data as below in the default bucket.
/opt/couchbase/bin/cbworkloadgen -r 1.0 -n localhost:8091 -s 10240 -b default -u Administrator -p password -t 4 -j -i 150000 -v
4. Create index with 1 replica.
CREATE INDEX `idx1` ON `default`(`name`,`body`) WITH

5. Let the index build completely.
6. Note the data_size stat for the index
7. On node2, kill indexer - pkill -f indexer
8. After a few mins, note the data_size stat for the index.

Issue : Data size for the index keeps on increasing about 20-35% each time the index recovery takes place.

In my test, here is the data size captured after recovery
Initial : "default:idx1:data_size": 3179952511
After 1st recovery : "default:idx1:data_size": 4279274374
After 2nd recovery : "default:idx1:data_size": 5378591480