[ez][CH] Fix infra_metrics.cloud.watch_metrics schema: use DateTime64 (#6909)

The timestamp used by cloudwatch has milliseconds, so change the
timestamp field to match that

Testing: replaced the old table, then ran `python
tools/rockset_migration/s32ch.py --clickhouse-table
"infra_metrics.cloudwatch_metrics" --stored-data t.json --s3-bucket
fbossci-cloudwatch-metrics --s3-prefix ghci-related `

Author: clee2000

aws/lambda/clickhouse-replicator-s3/lambda_function.py

@@ -552,7 +552,7 @@ def cloudwatch_metrics_adapter(table, bucket, key):
     `namespace` LowCardinality(String),
     `metric_name` LowCardinality(String),
     `dimensions` Map(String, String),
-    `timestamp` DateTime,
+    `timestamp` DateTime64,
     `value` Tuple(
         max Float32,
         min Float32,

clickhouse_db_schema/infra_metrics.cloudwatch_metrics/schema.sql

@@ -6,7 +6,7 @@ CREATE TABLE infra_metrics.cloudwatch_metrics
     `namespace` LowCardinality(String),
     `metric_name` LowCardinality(String),
     `dimensions` Map(String, String),
-    `timestamp` DateTime,
+    `timestamp` DateTime64,
     `value` Tuple(
         max Float32,
         min Float32,
@@ -20,5 +20,5 @@ CREATE TABLE infra_metrics.cloudwatch_metrics
 ENGINE = SharedMergeTree('/clickhouse/tables/{uuid}/{shard}', '{replica}')
 PARTITION BY toYYYYMM(timestamp)
 ORDER BY (namespace, metric_name, timestamp, dimensions)
-TTL timestamp + toIntervalMonth(12)
+TTL toDateTime(timestamp) + toIntervalMonth(12)
 SETTINGS index_granularity = 8192