Add support for simulcast with Vp8 from caller into PC level quality tests.

Add support of negotiating simulcast offer/answer. Also fix some minor
issues around to make it finally work.

Bug: webrtc:10138
Change-Id: I382f5df04ca6ac04d8ed1e030e7b2ae5706dd10c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/137425
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Amit Hilbuch <amithi@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28274}
diff --git a/test/DEPS b/test/DEPS
index 80c4719..02810f2 100644
--- a/test/DEPS
+++ b/test/DEPS
@@ -57,5 +57,9 @@
   ],
   ".*peer_connection_quality_test\.(h|cc)": [
     "+pc",
+  ],
+  ".*sdp_changer\.(h|cc)": [
+    "+pc",
+    "+p2p",
   ]
 }