Unsupported value error when using `setParameters` on `RTCRtpSender` due to  `mapToRtpParameters` not being implemented.

**Describe the bug**
When using unified-plan and calling `setParameters` on `RTCRtpSender` an `unsupported value` error gets thrown because it is being sent `null` and `nil` on Android and iOS respectively due to `mapToRtpParameters` not being implemented.

**Expected behavior**
The function should set and update RtpParameters correctly.