Removing private api from price oracle

[Andrewsopoku]

Issue

• Link: https://github.com/NebraLtd/maker-starter-app/issues/161
• Summary: Antenna update fee is incorrect.

How

Screenshots

References

Checklist

• [ ] Tests added
• [ ] Cleaned up commit history (rebase!)
• [ ] Documentation added
• [ ] Thought about variable and method names