Add new action for the storage manager settings.

Bug: 28560570
Change-Id: I7a17feff51c96634bfcc7d238ab168f0878e0e62
diff --git a/proto/src/metrics_constants.proto b/proto/src/metrics_constants.proto
index 4a98854..1c12565 100644
--- a/proto/src/metrics_constants.proto
+++ b/proto/src/metrics_constants.proto
@@ -2235,6 +2235,10 @@
     // Subtype: Index of selection
     ACTION_APP_DISAMBIG_TAP = 457;
 
+    // OPEN: Settings > Internal storage > Storage manager
+    // CATEGORY: SETTINGS
+    STORAGE_MANAGER_SETTINGS = 458;
+
     // Add new aosp constants above this line.
     // END OF AOSP CONSTANTS
   }