Add DHCP leases to the facts return by the module (#19700)

On RHEL 6, where the feature is not present, this will
be ignored and return nothing.

lib/ansible/modules/cloud/misc/virt_net.py

@@ -369,6 +369,10 @@ class LibvirtConnection(object):
         state = self.find_entry(entryid).isPersistent()
         return ENTRY_STATE_PERSISTENT_MAP.get(state,"unknown")
 
+    def get_dhcp_leases(self, entryid):
+        network = self.find_entry(entryid)
+        return network.DHCPLeases()
+
     def define_from_xml(self, entryid, xml):
         if not self.module.check_mode:
             return self.conn.networkDefineXML(xml)
@@ -454,6 +458,11 @@ class VirtNetwork(object):
             results[entry]["state"] = self.conn.get_status(entry)
             results[entry]["bridge"] = self.conn.get_bridge(entry)
             results[entry]["uuid"] = self.conn.get_uuid(entry)
+            try:
+                results[entry]["dhcp_leases"] = self.conn.get_dhcp_leases(entry)
+            # not supported on RHEL 6
+            except AttributeError:
+                pass
 
             try:
                 results[entry]["forward_mode"] = self.conn.get_forward(entry)