Info log level on Performance tests (#3667)

We don't need the full debug level on Agones for performance tests,
especially since it brings us close to the quota limits on log writes.

Also updated the order of variables to make it a bit more readable.

build/performance-test.sh

@@ -35,7 +35,7 @@ gcloud config set project $PROJECT
 gcloud container clusters get-credentials $CLUSTER_NAME \
         --zone=$CLUSTER_LOCATION --project=$PROJECT
 
-DOCKER_RUN= make install REGISTRY='"'$REGISTRY'"' 
+make install LOG_LEVEL=info REGISTRY='"'$REGISTRY'"' DOCKER_RUN=""
 
 cd /go/src/agones.dev/agones/test/load/allocation