Support for Opus 8000 Hz Mono on Android WebRTC?

I’m working with the Android WebRTC API and I noticed that the default audio track only allows Opus at 48kHz.

I want to know:

Is it possible to adjust the SDP to use Opus at 8000 Hz, mono (1 channel) on Android?

If not directly, is there a recommended workaround to send low-bandwidth Opus (8kHz) from Android WebRTC