AEC3: Correct peak index at filter size reductions
AEC3: Correct peak index at filter size reductions

Bug: chromium:1061933
Change-Id: I70745b82de1d8878d4a789c86af6a44e652c3e9e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/172420
Commit-Queue: Per Åhgren <3616c2c8a2c30a769c5419f89b4a810ea6e2f079@webrtc.org>
Reviewed-by: Sam Zackrisson <b1a93beadfe1d2f7f0106ee02b6ffcdc950aa103@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#30947}

TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc