config: regenerate upload config

This is an automated CL which updates the generated upload config.

[git-generate]
go generate ./internal/configgen

Change-Id: Ia477ac9e03b7cc1ea5402912ce3cf96e1097b6d3
Reviewed-on: https://go-review.googlesource.com/c/telemetry/+/715620
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Gopher Robot <gobot@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Madeline Kalil <mkalil@google.com>
diff --git a/config/config.json b/config/config.json
index 97456b6..9187038 100644
--- a/config/config.json
+++ b/config/config.json
@@ -537,6 +537,7 @@
 				"v0.51.3",
 				"v0.51.4",
 				"v0.51.5",
+				"v0.51.6",
 				"v0.52.0",
 				"v0.52.1",
 				"v0.52.2",