Change service call in async way

[DenisBalan]

Changed calls that support TAP model to use await syntax

Purpose

• Code style formatting in terms of using proper asynchronous model for Program.cs file.

Does this introduce a breaking change?

[ ] Yes
[x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[ ] Feature
[x] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

[msftclas]

All CLA requirements met.