fix example

Author: mihretkidane-OCI

src/Oracle/Oracle.Autorest/examples/Invoke-AzOracleActionDbNode.md

@@ -4,7 +4,7 @@ $vmClusterName = "OFake_PowerShellTestVmCluster"
 $resourceGroup = "PowerShellTestRg"
 $stopActionName = "Stop"
             
-$dbNodeList = Get-AzOracleDbNode -exadbVmClusterName $vmClusterName -ResourceGroupName $resourceGroup
+$dbNodeList = Get-AzOracleExascaleDbNode -exadbVmClusterName $vmClusterName -ResourceGroupName $resourceGroup
 $dbNodeOcid1 = $dbNodeList[0].Name
             
 Invoke-AzOracleActionDbNode -ResourceGroupName $resourceGroup -exadbVmClusterName $vmClusterName -Dbnodeocid $dbNodeOcid1  -Action $stopActionName