WebRTC.Audio.InitRecordingDurationMs and WebRTC.Audio.StartRecordingDurationMs UMA stats are added on Android to measure the time consumed on these two methods where the main part of the work is done in Java. Bug: b/67854242 Change-Id: I2d5487511402db18009d66a39c66d3f10d98cdd6 Reviewed-on: https://webrtc-review.googlesource.com/37420 Reviewed-by: Sam Zackrisson <saza@webrtc.org> Commit-Queue: Henrik Andreassson <henrika@webrtc.org> Cr-Commit-Position: refs/heads/master@{#21494}