devserver metrics: fix a metric name issue

This CL fixes a wrong metric name.

BUG=None
TEST=None

Change-Id: Id65ebdc3f0c2b7cccc5407c44a0a501b0738e256
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/1823360
Reviewed-by: Congbin Guo <guocb@chromium.org>
Commit-Queue: Congbin Guo <guocb@chromium.org>
Tested-by: Congbin Guo <guocb@chromium.org>
Auto-Submit: Congbin Guo <guocb@chromium.org>
diff --git a/apache_log_metrics.py b/apache_log_metrics.py
index b2b2349..b07b48c 100755
--- a/apache_log_metrics.py
+++ b/apache_log_metrics.py
@@ -188,7 +188,7 @@
   except ValueError:  # Zero is represented by "-"
     size = 0
 
-  metrics.Counter(STATIC_GET_METRIC_NAME).increment_by(
+  metrics.Counter(DEVSERVER_RPC_USAGE_METRIC_NAME).increment_by(
       size, fields={
           'http_method': m.group('http_method'),
           'rpc_name': m.group('rpc_name'),