Add Winscope sync metadata to screen recording

Winscope tool requires frame presentation time relative to
android::elapsedRealtimeNano to synchronise video with SurfaceFlinger
and WindowManager traces. The metadata is stored as a separate data
track in the MPEG-4 container.

Design doc: http://go/winscope-video-sync

Test: adb shell screenrecord /sdcard/test.mp4 --time-limit 5
Bug:
Change-Id: I4536956efe8c62a0586b55bab1db6bdf368d4348