LastImportTime for resource. (#112153)

* LastImportTime for resource.

* Make StorageBackendImpl implement GetResourceLastImportTimes

* More missing implementations of GetResourceLastImportTimes

* Fix import.

* Skip TestGetResourceLastImportTime in TestBadgerKVStorageBackend.

* Implement GetResourceLastImportTimes by mockStorageBackend

* Bump test tolerance.

* Fix postgres query and timezone.

* Fix postgres query and timezone.

* Make linter happy.

pkg/storage/unified/sql/queries.go

@@ -58,6 +58,9 @@ var (
 
 	sqlResourceBlobInsert = mustTemplate("resource_blob_insert.sql")
 	sqlResourceBlobQuery  = mustTemplate("resource_blob_query.sql")
+
+	sqlResourceLastImportTimeInsert = mustTemplate("resource_last_import_time_insert.sql")
+	sqlResourceLastImportTimeQuery  = mustTemplate("resource_last_import_time_query.sql")
 )
 
 // TxOptions.
@@ -454,3 +457,35 @@ func (r sqlResourceListModifiedSinceRequest) Validate() error {
 	}
 	return nil
 }
+
+type sqlResourceLastImportTimeInsertRequest struct {
+	sqltemplate.SQLTemplate
+	Namespace      string
+	Group          string
+	Resource       string
+	LastImportTime time.Time
+}
+
+func (r sqlResourceLastImportTimeInsertRequest) Validate() error {
+	if r.Namespace == "" {
+		return fmt.Errorf("missing namespace")
+	}
+	if r.Group == "" {
+		return fmt.Errorf("missing group")
+	}
+	if r.Resource == "" {
+		return fmt.Errorf("missing resource")
+	}
+	if r.LastImportTime.IsZero() {
+		return fmt.Errorf("last import time cannot be zero")
+	}
+	return nil
+}
+
+type sqlResourceLastImportTimeQueryRequest struct {
+	sqltemplate.SQLTemplate
+}
+
+func (r *sqlResourceLastImportTimeQueryRequest) Validate() error {
+	return nil
+}