Validation tests: remove toguid casting

Host_OMSAgentID - removed casting to guid

Exploration Queries/InputEntity_Account/Acc2Host_HostWithMostFails.yaml

@@ -54,7 +54,7 @@ query: |
   | top 10 by Host_Aux_FailedLoginsCount
   | parse Computer with Host_NTDomain '\\' *
   | extend Host_HostName = tostring(split(Computer,'.')[0]), 
-   Host_DnsDomain = strcat_array(array_slice(split(Computer,'.'),1,256),'.'), Host_OMSAgentID=toguid(SourceComputerId), Host_AzureID = _ResourceId
+   Host_DnsDomain = strcat_array(array_slice(split(Computer,'.'),1,256),'.'), Host_OMSAgentID=SourceComputerId, Host_AzureID = _ResourceId
   | project-away Computer, Account, _ResourceId, SourceComputerId
   };
   MostFailedLogins('<Name>','<NTDomain>','<UPNSuffix>')