Validation of Impact of Configuration Switch Optimization on Language Service Initialization

[kvenkatrajan]

@## Summary

This is a placeholder item to validate the performance improvements for Configuration switch optimization code

• [x] Functional Testing : #7541
• [x] Validate if #7615 occurs
• [x] Validate if AB#1439046 occurs
• [ ] Coordinate with Roslyn team to add speedometer test for this scenario
• [ ] Add/use telemetry values to capture time from configuration switch to intellisense

Impact

Will help identify the impact & add tests to identify regression in the future