core: handle missing allocation policy/format when converting

If allocation policy or format were not passed to the disk conversion
endpoint it will fail to setup monitoring because of NPE.

This patch uses the existing allocation policy or format when it's
missing to generate the message.

Bug-Url: https://bugzilla.redhat.com/2076042
Signed-off-by: Benny Zlotnik <bzlotnik@redhat.com>

backend/manager/modules/bll/src/main/java/org/ovirt/engine/core/bll/storage/disk/image/ConvertDiskCommand.java

@@ -374,10 +374,18 @@ protected LockProperties applyLockProperties(LockProperties lockProperties) {
     @Override
     public Map<String, String> getJobMessageProperties() {
         if (jobProperties == null) {
+            String allocationPolicy = getParameters().getPreallocation() != null ?
+                    getParameters().getPreallocation().toString() :
+                    getDiskImage().getVolumeType().toString();
+
+            String diskFormat = getParameters().getVolumeFormat() != null ?
+                    getParameters().getVolumeFormat().toString() :
+                    getDiskImage().getVolumeFormat().toString();
+
             jobProperties = super.getJobMessageProperties();
             jobProperties.put("diskname", getDiskImage().getName());
-            jobProperties.put("allocationpolicy", getParameters().getPreallocation().toString());
-            jobProperties.put("diskformat", getParameters().getVolumeFormat().toString());
+            jobProperties.put("allocationpolicy", allocationPolicy);
+            jobProperties.put("diskformat", diskFormat);
         }
 
         return super.getJobMessageProperties();