Make GCP proxy log in a Stackdriver logging compliant format

When not running locally, the logging formatter is set to convert the log record to a single-line JSON string that Stackdriver logging agent running in GKE will pick up and parse correctly.

Also removed redundant logging handler in the proxy frontend connection. They have two problems: 1) it is possible to leak PII when all frontend traffic is logged, such as client IPs. Even though this is less of a concern because the GCP TCP proxy load balancer masquerade source IPs. 2) We are only logging the HTTP request/response that the frontend connection is sending to/receiving from the backend connection, but the backend already has its own logging handler to log the same message that it gets from/sends to the GAE app, so the logging in the frontend connection does not really give extra information.
Logging of some potential PII information such as the source IP of a proxied connection are also removed.

Thirdly, added a k8s autoscaling object that scales the containers based on CPU load. The default target load is 80%. This, in connection with GKE cluster VM autoscaling, means that when traffic is low, we'll only have one VM running one container of the proxy.

Fixes a bug where the MetricsComponent generates a separate ProxyConfig that does not call parse method on the command line args passed, resulting default Environment always being used in constructing the metric reporter.

Lastly a little bit of cleaning of the MOE config script, no newlines are necessary as the BUILD are formatted after string substitution.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=188029019

java/google/registry/proxy/handler/SslServerInitializer.java

@@ -68,7 +68,7 @@ public class SslServerInitializer<C extends Channel> extends ChannelInitializer<
       SslProvider sslProvider,
       PrivateKey privateKey,
       @Named("eppServerCertificates") X509Certificate... certificates) {
-    logger.finefmt("Server SSL Provider: %s", sslProvider);
+    logger.infofmt("Server SSL Provider: %s", sslProvider);
     this.sslProvider = sslProvider;
     this.privateKey = privateKey;
     this.certificates = certificates;