Add metric id for Mobile network page

Change-Id: I66c4018465e7287d43ae2e53282dc92739e634ec
Fixes: 114444242
Test: Build
diff --git a/proto/src/metrics_constants.proto b/proto/src/metrics_constants.proto
index 7edcdcb..41b3feb 100644
--- a/proto/src/metrics_constants.proto
+++ b/proto/src/metrics_constants.proto
@@ -6512,6 +6512,11 @@
     // OS: Q
     SETTINGS_GESTURE_WAKE_SCREEN = 1570;
 
+    // OPEN: Settings > Network & internet > Mobile network
+    // CATEGORY: SETTINGS
+    // OS: Q
+    MOBILE_NETWORK = 1571;
+
     // ---- End Q Constants, all Q constants go above this line ----
 
     // Add new aosp constants above this line.