Fix console build for GKE (#2713)

We use the $environment property to set the console config. If it is not
given, 'alpha' is used, which has the same effect as 'production'.

TESTED=ran :jetty:copyConsole with
-Penvironment=(sandbox|production|alpha) and checked the resulting js
file.

release/build_nomulus_for_env.sh

@@ -51,7 +51,7 @@ else
     mv services/"${service}"/build/staged-app "${dest}/${service}"
   done
 
-  ./gradlew :console-webapp:buildConsoleWebapp -Pconfiguration="${environment}"
+  ./gradlew :console-webapp:buildConsoleWebapp -Penvironment="${environment}"
   mkdir -p "${dest}/console" && cp -r console-webapp/staged/* "${dest}/console"
 
   mv core/build/resources/main/google/registry/env/common/META-INF \