Revert of Add full stack tests for MediaCodec. (patchset #10 id:180001 of https://codereview.webrtc.org/3005253002/ )

Reason for revert:
Breaks KitKat/Lollipop perf bots.

Original issue's description:
> Add full stack tests for MediaCodec encoder.
>
> * Add audio_ prefix to CallTest::{en,de}coder_factory_.
> * Let VideoQualityTest only instantiate encoders using encoder factories.
> * Add HW encoder factories to VideoQualityTest.
> * Add full stack tests:
>   - sqcif7 at  30 kbps: MediaCodec and libvpx.
>   - 240p10 at 100 kbps: MediaCodec, libvpx, and MediaCodec+libvpx.
>
> BUG=webrtc:8219
>
> Review-Url: https://codereview.webrtc.org/3005253002
> Cr-Commit-Position: refs/heads/master@{#19923}
> Committed: https://webrtc.googlesource.com/src/+/2cefac6c1685abfcd7b90fdef8e926f1c2b79bfa

TBR=sprang@webrtc.org,asapersson@webrtc.org,kjellander@webrtc.org,stefan@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:8219

Review-Url: https://codereview.webrtc.org/3016593002
Cr-Commit-Position: refs/heads/master@{#19926}