Adding EnrollmentReader role to Service Principal

[KalpeshBhandari]

Adding Enrollment Reader role to an existing Service Principal in this case Azure App is a complicated process, for role addition it should as simple as adding Reader, Billing Reader and Cost Mangement Reader roles

[#2]

@KalpeshBhandari 

Are you considering custom role?

[#3]

@Kidd_Ip 

I think it should more out of the box Role like we chose 'Cost Management Reader' Role