added missing file

Signed-off-by: Gustavo Carvalho <gustavo.carvalho@container-solutions.com>

apis/externalsecrets/v1beta1/secretsink_interfaces.go

@@ -0,0 +1,19 @@
+/*
+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.
+*/
+package v1beta1
+
+// This interface is to allow using v1alpha1 content in Provider registered in v1beta1.
+type PushRemoteRef interface {
+	GetRemoteKey() string
+}