Add activity reporting SQL query generation code

This allows us to have a modular view of all tables used in activity reporting, to facilitate generating reports in BigQuery.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=161849007

java/google/registry/reporting/sql/dns_counts.sql

@@ -0,0 +1,33 @@
+  -- Copyright 2017 The Nomulus Authors. All Rights Reserved.
+  --
+  -- Licensed under the Apache License, Version 2.0 (the "License");
+  -- you may not use this file except in compliance with the License.
+  -- You may obtain a copy of the License at
+  --
+  --     http://www.apache.org/licenses/LICENSE-2.0
+  --
+  -- Unless required by applicable law or agreed to in writing, software
+  -- distributed under the License is distributed on an "AS IS" BASIS,
+  -- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  -- See the License for the specific language governing permissions and
+  -- limitations under the License.
+
+  -- Query for DNS metrics.
+
+  -- Our DNS provider exports logs for all queries received. However, these
+  -- tables only have a TTL of 7 days. We make daily exports of the data
+  -- relevant to us, which allows us to get the full month's UDP and TCP
+  -- queries when generating activity reports.
+
+SELECT
+  -- DNS metrics apply to all tlds, which requires the 'null' magic value.
+  STRING(NULL) AS tld,
+  metricName,
+  -- TODO(b/63388735): Change this to actually query the DNS tables when ready.
+  -1 AS count,
+FROM (
+  SELECT
+    'dns-udp-queries' AS metricName),
+  (
+  SELECT
+    'dns-tcp-queries' AS metricName)