Add a photos app filter and a metric for using it.

Bug: 64147318
Test: SettingsLib integ tests

Change-Id: Id165a514aa65d2efdd4e6753c3e73762293e892e
Merged-In: I4cae384fa565ac0928177bd85804d7904cd6156c
diff --git a/proto/src/metrics_constants.proto b/proto/src/metrics_constants.proto
index a287254..1d6e76f 100644
--- a/proto/src/metrics_constants.proto
+++ b/proto/src/metrics_constants.proto
@@ -4282,6 +4282,11 @@
     // the app transition.
     APP_TRANSITION_REPORTED_DRAWN_MS = 1091;
 
+    // OPEN: Settings > Storage > Photos & Videos
+    // CATEGORY: SETTINGS
+    // OS: O MR
+    APPLICATIONS_STORAGE_PHOTOS = 1092;
+
     // Add new aosp constants above this line.
     // END OF AOSP CONSTANTS
   }