Delete obsolete BitrateAdjuster constructor.
Delete obsolete BitrateAdjuster constructor.

Followup to https://webrtc-review.googlesource.com/70381

Bug: webrtc:6733
Change-Id: I8c83ab17836f71b35ec5f05b24f1be3b6bbe7fe1
Reviewed-on: https://webrtc-review.googlesource.com/71081
Reviewed-by: Magnus Jedvert <9507adee858471ab168c339dc72b814b168c081b@webrtc.org>
Commit-Queue: Niels Moller <0057859e47d61d90529d0f66d9ef692cefedb46a@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#22950}
TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc