[VMware] Consider CD/DVD drive when calculating next free unit number for volume attachment over IDE controller (#9644)

Co-authored-by: dahn <daan.hoogland@gmail.com>

Author: winterhazel

vmware-base/src/main/java/com/cloud/hypervisor/vmware/mo/VirtualMachineMO.java

@@ -3169,9 +3169,12 @@ public int getFreeUnitNumberOnIDEController(int controllerKey) throws Exception
 
         int deviceCount = 0;
         int ideDeviceUnitNumber = -1;
-        if (devices != null && devices.size() > 0) {
+        if (devices != null) {
             for (VirtualDevice device : devices) {
-                if (device instanceof VirtualDisk && (controllerKey == device.getControllerKey())) {
+                if (device.getControllerKey() == null || device.getControllerKey() != controllerKey) {
+                    continue;
+                }
+                if (device instanceof VirtualDisk || device instanceof VirtualCdrom) {
                     deviceCount++;
                     ideDeviceUnitNumber = device.getUnitNumber();
                 }