Add Power mode sample for GG

[josesimoes]

Description

Motivation and Context

How Has This Been Tested?

Screenshots

Types of changes

• [ ] Improvement (non-breaking change that improves a sample)
• [ ] Bug fix (fixes an issue with a current sample)
• [x] New Sample (adds a new sample)
• [ ] Config and build (change in the configuration and build system, has no impact on code or features)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.