[DCAEGEN2-SERVICES] Fix and resolve remote references in st. def. domain

As it was agreed with Vijay we are downgrading
standard defined domain used in OOM to version
that is compatible with helm charts and config
map size used during ONAP deployment.
In order to upgrade schema map user need to use
OOM/UTILS script and update deployments of:
- dcae ves collector
- dcae ves openapi manager

Signed-off-by: Krzysztof Kuzmicki <krzysztof.kuzmicki@nokia.com>
Issue-ID: DCAEGEN2-2893 DCAEGEN2-2894 DCAEGEN2-2895
Change-Id: I09caa95041cf9bd5825d384eaf513cfecf24044d
diff --git a/kubernetes/dcaegen2-services/resources/external/schemas/sa88-rel16/heartbeatNtf.yaml b/kubernetes/dcaegen2-services/resources/external/schemas/sa88-rel16/heartbeatNtf.yaml
new file mode 100644
index 0000000..afde506
--- /dev/null
+++ b/kubernetes/dcaegen2-services/resources/external/schemas/sa88-rel16/heartbeatNtf.yaml
@@ -0,0 +1,23 @@
+openapi: 3.0.1
+info:
+  title: Heartbeat notification
+  version: 16.3.0
+  description: >-
+    OAS 3.0.1 specification of the heartbeat notification
+    © 2020, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC).
+    All rights reserved.
+externalDocs:
+  description: 3GPP TS 28.532 V16.3.0; Heartbeat notification
+  url: http://www.3gpp.org/ftp/Specs/archive/28_series/28.6532/
+paths: {}
+components:
+  schemas:
+    hearbeatNtfPeriod-Type:
+      type: integer
+    notifyHeartbeat-NotifType:
+      allOf:
+        - $ref: 'provMnS.yaml#/components/schemas/header-Type'
+        - type: object
+          properties:
+            heartbeatNtfPeriod:
+              $ref: '#/components/schemas/hearbeatNtfPeriod-Type'