Expand video frame metadata cache

In simulcast screenshare the lower stream can be disabled for ~2 seconds
due to bandwidth limitations. During that time with 30 input fps more
than 50 frames can be pending.

This CL remove unnecessary warnings.

Bug: webrtc:4172
Change-Id: I979c946a03ff3f67f500843c66382e437ecd559b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/134041
Reviewed-by: Johannes Kron <kron@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27735}

modules/video_coding/include/video_coding_defines.h

@@ -40,7 +40,7 @@ enum {
   kDefaultTimingFramesDelayMs = 200,
   kDefaultOutlierFrameSizePercent = 500,
   // Maximum number of frames for what we store encode start timing information.
-  kMaxEncodeStartTimeListSize = 50,
+  kMaxEncodeStartTimeListSize = 150,
 };
 
 enum VCMVideoProtection {