Add Night display feature

Bug: 28615069

Tints the display at night automatically according to your schedule or
using the sunrise/sunset corresponding to your current location.

Change-Id: Ie56b4eed88cc2fcbae88002492b1edad5820b6b1
diff --git a/proto/src/metrics_constants.proto b/proto/src/metrics_constants.proto
index 1fb9642..45e3e7e 100644
--- a/proto/src/metrics_constants.proto
+++ b/proto/src/metrics_constants.proto
@@ -2367,6 +2367,10 @@
     // ACTION: Settings -> Support -> "Travel Abroad" Button -> Tolled Phone
     ACTION_SUPPORT_DIAL_TOLLED = 487;
 
+    // OPEN: Settings > Display > Night display
+    // CATEGORY: SETTINGS
+    NIGHT_DISPLAY_SETTINGS = 488;
+
     // ---- End N-MR1 Constants, all N-MR1 constants go above this line ----
     // Add new aosp constants above this line.
     // END OF AOSP CONSTANTS