This reverts commit 86e0ea5711.
Reason for revert: The reasons for removing bitratePriority are unclear. Aside from the fact that you can't yet use it for the relative bitrate of simulcast streams, only the relative bitrate of entire tracks, it's working as intended. It differs from the standard, but only in that it's more flexible; the web standard only allows values of 0.5, 1.0, 2.0, and 4.0 while for the native API we allow any ratio.
Original change's description:
> Remove bitratePriority from the Obj-C RTCRtpEncodingParameters wrapper.
>
> This was added in CL 135122, but the bitratePriority parameter is not
> standard and not implemented in a way users would expect. So it should
> actually not be exposed in the Obj-C SDK.
>
> Bug: webrtc:10438
> Change-Id: I801ce940a32701d2703e951ef2b601c606aa2111
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/135287
> Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
> Commit-Queue: Anders Carlsson <andersc@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#27861}
TBR=andersc@webrtc.org,kthelgason@webrtc.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: webrtc:10438
Change-Id: Ibc16b6054a1583de43a868d98683ea114bd89435
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/171140
Reviewed-by: Taylor <deadbeef@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30863}
f05af9e0fc