Clean up script analyzer warnings for Update-AutomationAzureModulesForAccount

[xandersherry]

When checking the Update-AutomationAzureModulesForAccount.ps1 runbook with ScriptAnalyzer, the following warnings are generated.

WARNING: Update-AzureAutomationModulesForAccount.ps1 (Line 166): 'Add-AzureRmAccount' is an alias of 'Connect-AzureRmAccount'. Alias can introduce possible problems and make scripts hard to maintain. Please consider changing alias to its full content.

WARNING: Update-AzureAutomationModulesForAccount.ps1 (Line 173): 'Select-AzureRmSubscription' is an alias of 'Set-AzureRmContext'. Alias can introduce possible problems and make scripts hard to maintain. Please consider changing alias to its full content.