core: look for InstanceID as well when reading internal ovfs

Issue:
When attaching SD, VM Import tab doesn't show a VM if VM OVF has 'InstanceID' instead of 'InstanceId' property. The engine log shows the below error.
'Error parsing OVF due to OVF error: ol8-clone: cannot read 'rasd:InstanceId' with value: null'.
Ref bug change https://bugzilla.redhat.com/show_bug.cgi?id=1850103

Fix:
When reading/parsing VM OVF, check for both values 'InstanceID' and 'InstanceId'.

Signed-off-by: Shubha Kulkarni <shubha.kulkarni@oracle.com>

backend/manager/modules/utils/src/main/java/org/ovirt/engine/core/utils/ovf/OvfOvirtReader.java

@@ -146,6 +146,17 @@ private XmlNode getNode(XmlNodeList nodeList, String attributeName, String attri
         return null;
     }
 
+    protected String getInstanceIdValue(XmlNode node) {
+        XmlNode candidateNode = selectSingleNode(node, "rasd:InstanceId", _xmlNS);
+        // Some OVFs have InstanceID instead of InstanceId (e.g. generated by Oracle)
+        // So check for both values in the xml node
+        if (candidateNode == null) {
+            candidateNode = selectSingleNode(node, "rasd:InstanceID", _xmlNS);
+        }
+
+        return candidateNode.innerText;
+    }
+
     protected void readSnapshotsSection(@SuppressWarnings("unused") XmlNode section) {
         // The snapshot section only has meaning for VMs, and is overridden in OvfVmReader.
     }
@@ -261,7 +272,7 @@ protected void readDisk(XmlNode node, DiskImage image) {
     @Override
     protected VmNetworkInterface getNetworkInterface(XmlNode node) {
         // prior to 3.0 the instanceId is int , in 3.1 and on this is Guid
-        String str = selectSingleNode(node, VMD_ID, _xmlNS).innerText;
+        String str = getInstanceIdValue(node);
         if (!StringUtils.isNumeric(str)) { // 3.1 and above OVF format
             final Guid guid = new Guid(str);
             VmNetworkInterface iface = interfaces.stream().filter(i -> i.getId().equals(guid)).findFirst().orElse(null);
@@ -329,7 +340,8 @@ protected void readOsSection(XmlNode section) {
 
     @Override
     protected void readDiskImageItem(XmlNode node) {
-        final Guid guid = new Guid(selectSingleNode(node, VMD_ID, _xmlNS).innerText);
+        String str = getInstanceIdValue(node);
+        final Guid guid = new Guid(str);
         DiskImage image = _images.stream().filter(d -> d.getImageId().equals(guid)).findFirst().orElse(null);
         if (image == null) {
             return;