Enable the feature flag for geo-shape decimation by default

This is the follow-up of the MR Geoshape decimation.

We enabled the feature flags in two data partitions on 12/6/2022 and shape decimation was applied to the new ingested data with geo-shapes from different users. We didn't see any problem on the shape decimation so far.

This MR is to enable the feature flag of the shape decimation for all data partitions by default. Client can still disable this feature in a given data partition through the Partition Service:

{
   "indexer-decimation-enabled": {
        "sensitive": false,
        "value": "false"
    }
}