Suez: Implement display wake reason stats

Bug: 150519505
Bug: 157700750
Test: <screen off>
      adb shell cmd stats print-logs # stats log on
      adb shell input keyevent KEYCODE_POWER;
      adb shell input keyevent KEYCODE_POWER;
      adb shell input keyevent KEYCODE_WAKEUP;
      adb logcat

      logs:
      statsd  : { uid(1000) 1590662902 47548877729 (282)0x10000->1[I]  }
      statsd  : { uid(1000) 1590662905 49953926700 (282)0x10000->6[I]  }

Change-Id: I82191ca3e41df7066bb61adfb25cd9dc194a5433
(cherry picked from commit 0850023c)