templates with diagnostic settings fail with trademark error

[101-redis-cache](https://github.com/Azure/azure-quickstart-templates/tree/master/101-redis-cache)

### Issue Details
Templates like this one that include a diagnosticsettings sub-resource fail validation with the message "The resource name 'myrediscache/Microsoft.Insights/service' or a part of the name is a trademarked or reserved word."

Start with the 101-redis-cache template linked in the issue and reproduce its validation failure involving the diagnosticsettings sub-resource. Compare the template's resource naming with the reported trademarked-word error; the work is done when the template validates without that error.

Written by the indexing model from the issue text.