Fix issue with metrics-reporter-cloudwatch plugin download

Metrics-reporter-cloudwatch plugin should be downloaded with
metrics-reporter-cloudwatch.jar name instead of healthcheck.jar

Change-Id: Ic42cf5883fa493af89f7abb41fbfe4fd631ee375
diff --git a/gerrit/Makefile b/gerrit/Makefile
index af0f4b2..9b05b1f 100644
--- a/gerrit/Makefile
+++ b/gerrit/Makefile
@@ -31,7 +31,7 @@
 
 	@echo "Downloading Metrics Reporter Cloudwatch plugin $(GERRIT_BRANCH)"
 	wget $(GERRIT_CI)/plugin-metrics-reporter-cloudwatch-bazel-$(GERRIT_BRANCH)/$(LAST_BUILD)/metrics-reporter-cloudwatch/metrics-reporter-cloudwatch.jar \
-	-O ./plugins/healthcheck.jar \
+	-O ./plugins/metrics-reporter-cloudwatch.jar \
 	|| { echo >&2 "Cannot download metrics-reporter-cloudwatch plugin: Check internet connection. Aborting"; exit 1; }
 
 gerrit-build: