Custom Teams should support assigning roles in pre-defined Teams

Customers would like to assign roles in pre-defined teams to custom teams. This would allow customers to assign all roles needed to custom teams instead of building custom teams and mapping groups to both custom teams and pre-defined teams. For example, say a custom team need access to CP X and also Analytics Viewer only roles. Today this requires creating a custom Team, then mapping a group to the custom Team and the Analytics Viewer predefined Team. This would also simplify audits because we could just look at the custom team to determine what members have access in the platform.