Move GCP proxy code to the old [] proxy's location

1. Moved code for the GCP proxy to where the [] proxy code used to live.
3. Corrected reference to the GCP proxy location.
4. Misc changes to make ErrorProne and various tools happy.

+diekmann to LGTM terraform whitelist change.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=213630560

java/google/registry/proxy/terraform/modules/kms.tf

@@ -0,0 +1,15 @@
+resource "google_kms_key_ring" "proxy_key_ring" {
+  name     = "${var.proxy_key_ring}"
+  location = "global"
+}
+
+resource "google_kms_crypto_key" "proxy_key" {
+  name     = "${var.proxy_key}"
+  key_ring = "${google_kms_key_ring.proxy_key_ring.id}"
+}
+
+resource "google_kms_crypto_key_iam_member" "ssl_key_decrypter" {
+  crypto_key_id = "${google_kms_crypto_key.proxy_key.id}"
+  role          = "roles/cloudkms.cryptoKeyDecrypter"
+  member        = "serviceAccount:${google_service_account.proxy_service_account.email}"
+}