Revert "MB-47502: Temporarily disable stats pruning as it causes ..."

This reverts commit d7c270c618c29e29d27d8fff74e156167d8fb79b.

Change-Id: I7f04ee2d81bf2b5a978f4386aae3b96c4e1f9df5
Reviewed-on: http://review.couchbase.org/c/ns_server/+/158973
Well-Formed: Restriction Checker
Tested-by: Timofey Barmin <[email protected]>
Reviewed-by: Timofey Barmin <[email protected]>

Author: timofey-barmin

src/prometheus_cfg.erl

@@ -148,8 +148,8 @@ default_settings() ->
      {scrape_interval, 10}, %% in seconds
      {scrape_timeout, 10}, %% in seconds
      {snapshot_timeout_msecs, 30000}, %% in milliseconds
-     {decimation_enabled, false},
-     {truncation_enabled, false},
+     {decimation_enabled, true},
+     {truncation_enabled, true},
      {decimation_defs, decimation_definitions_default()},
      {pruning_interval, 60000}, %% frequency to try to prune stats (msecs)
      {truncate_max_age, 3*?SECS_IN_DAY}, %% age (secs) to truncate stats