Increase the number of points for Cobalt UI error charts

The data is less smooth after some recent changes to the error
calculation. Use more points to show the graph with a higher degree of
accuracy.

The load time is not noticeably impacted.

Change-Id: If96b1c806579f56c028fc3b6f27e78ac521fcd61
Reviewed-on: https://fuchsia-review.googlesource.com/c/cobalt/+/507160
Fuchsia-Auto-Submit: Jared Weinstein <jaredweinstein@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
Reviewed-by: Alexandre Zani <azani@google.com>
diff --git a/src/bin/config_parser/src/source_generator/json.go b/src/bin/config_parser/src/source_generator/json.go
index c0e3fe3..ce9d519 100644
--- a/src/bin/config_parser/src/source_generator/json.go
+++ b/src/bin/config_parser/src/source_generator/json.go
@@ -147,7 +147,7 @@
 		windowSize = append(windowSize, ws.String())
 	}
 
-	populations := linspace(10000, 10000000, 20)
+	populations := linspace(10000, 10000000, 50)
 	estimates := jo.makeErrorEstimates(report, metric, populations)
 
 	return jsonReport{