Add metrics for WallpaperPicker launch source

Bug: 154781896
Test: make statsd_testdrive; statsd_testdrive 179
Change-Id: I37aec888cc3208ec6d6e518d4a82682682213335
1 file changed
tree: 8dc450321c5ffceaa81bfa44b2bb27a9f89b428a
  1. bin/