Find VM by uuid should be fixed when trying to find VM by vc uuid

[pshahzeb]

findVmByUuid does si.content.searchIndex.FindByUuid and always passes 4th arg as False.
This should be true when vc uuid is used (by the caller of this function) and false when bios uuid is used.

See usage of FindByUuid on this page - https://www.vmware.com/support/developer/vc-sdk/visdk41pubs/ApiReference/vim.SearchIndex.html

Two parts to fix this:

1. when this util is invoked as part of attach/detach work flow
2. when this util is used as part of tenancy (db ops). While fixing this, backward compatibility shouldn't be broken.