
If instance memory is not multiple of 4, creating instance on ESXi fails with error "['GenericVmConfigFault'] VimFaultException: Memory (RAM) size is invalid.". However this is after instance is built and tried to launch on ESXi. Add check in prepare_for_spawn to trigger failure early and avoid further steps i.e. build as well as launch. Closes-Bug: #1966987 Change-Id: I7ed8ac986283cd455e54e3f18ab955f43b3248d0