Revert "Don't download PESQ and POLQA in the low_bandwidth_audio_test.py script."
Revert "Don't download PESQ and POLQA in the low_bandwidth_audio_test.py script."

This reverts commit 20196984558b890ee7648d5cc778bc055fdeb5b2.

Reason for revert: Fails on Mac
https://build.chromium.org/p/client.webrtc.perf/builders/Mac%2010.11/builds/4070

Original change's description:
> Don't download PESQ and POLQA in the low_bandwidth_audio_test.py script.
> 
> They should've been downloaded already.
> 
> NOTRY=True
> 
> Bug: chromium:755660
> Change-Id: I8ecb355f06026a38bd9377633e2be6c55d7c6452
> Reviewed-on: https://webrtc-review.googlesource.com/5620
> Commit-Queue: Edward Lemur <d05609f027dc667cc37492b1dc1bdea5d60fa82a@webrtc.org>
> Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
> Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#20109}

TBR=kjellander@webrtc.org,phoglund@webrtc.org,d05609f027dc667cc37492b1dc1bdea5d60fa82a@webrtc.org,oprypin@webrtc.org

Change-Id: I0cfc1d0b398587a023af528536e7d995c6de1413
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:755660
Reviewed-on: https://webrtc-review.googlesource.com/5940
Reviewed-by: Edward Lemur <d05609f027dc667cc37492b1dc1bdea5d60fa82a@webrtc.org>
Commit-Queue: Edward Lemur <d05609f027dc667cc37492b1dc1bdea5d60fa82a@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#20112}
ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc