Create single activity for rewrite rule

[rajkumar-rangaraj]

Addressing Issue #73

Changes

(Please provide a brief description of the changes here.)

Modified EndRequest in TelemetryCorrelationHttpModule to skip activity creation for rewrite generated parent request.

Background Information

Initial version of the TelemetryCorrelationHttpModule had this activity creation within Application_Error and later moved to EndRequest.

https://github.com/aspnet/Microsoft.AspNet.TelemetryCorrelation/pull/1/files https://github.com/aspnet/Microsoft.AspNet.TelemetryCorrelation/blob/cc1592d241fee1df40442790fddf7779c787e838/src/Microsoft.AspNet.Diagnostics/DiagnosticsHttpModule.cs

https://github.com/aspnet/Microsoft.AspNet.TelemetryCorrelation/pull/2 https://github.com/aspnet/Microsoft.AspNet.TelemetryCorrelation/blob/c0c6b8ce9e3f371c6012a2646e4a5f253fcaea41/src/Microsoft.AspNet.Diagnostics/DiagnosticsHttpModule.cs

Notes from PR

[dnfgituser]

All CLA requirements met.