Legacy channels say "allow sound" instead of "let the app decide".
We had this string already translated from use in previous ux revs.

Change-Id: I91a9ce001a0d875c0ae12643e6b386328e9cd8de
Fixes: 62873496
Test: String change, manually verified
diff --git a/res/values/strings.xml b/res/values/strings.xml
index a154135..b53dbde 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -6833,8 +6833,8 @@
     <!-- [CHAR LIMIT=100] Notification importance screen title -->
     <string name="notification_importance_title">Importance</string>
 
-    <!-- [CHAR LIMIT=100] Notification Importance: unspecified importance level description -->
-    <string name="notification_importance_unspecified">Let the app decide</string>
+    <!-- [CHAR LIMIT=100 BACKUP_MESSAGE_ID=1820188704793497324] Notification Importance: unspecified importance level description -->
+    <string name="notification_importance_unspecified">Allow sound</string>
 
     <!-- [CHAR LIMIT=100] Notification Importance: blocked importance level description -->
     <string name="notification_importance_blocked">Never show notifications</string>