VM Clone Sample constructs invalid VirtualMachineCloneSpec

[kumahesh]

Cloning vm from template failed. The sample constructs Clonespec by taking parameters from user input. If resource pool is not specified by user, It makes default choice by returning first resourcepool object under root folder. This default choice might belong to different datacenter than the one specified by user. To avoid this issue, it should search for default choice under datacenter, instead of searching root folder