* Increase 540p bitrate to 1.2mbps from 0.9mpbs. 960x540 bitrate was by far smallest in terms of bits per pixel. This change brings it closer to other resolutions. * Interpolate max/target/min bitrates for non-standard resolutions based on number of pixels. Bug: webrtc:10965 Change-Id: If0aa56bb4c614ca09ee39d3a2b700aab2ffa1a2c Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/152828 Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org> Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29195}