Add flag to guard if a user can see call failure error message if 2G is off

Test: m
Bug: b/300142897
Change-Id: Id8fb49d91af39c5d371476cb49ed7ad998e7cb88
diff --git a/flags/calling.aconfig b/flags/calling.aconfig
index 82f932b..e67ebc6 100644
--- a/flags/calling.aconfig
+++ b/flags/calling.aconfig
@@ -5,4 +5,11 @@
   namespace: "telephony"
   description: "APIs that are used to notify simultaneous calling changes to other applications."
   bug: "297446980"
+}
+
+flag {
+  name: "show_call_fail_notification_for_2g_toggle"
+  namespace: "telephony"
+  description: "Used in DisconnectCause and TelephonyConnection if a non-emergency call fails on a device with no 2G, to guard whether a user can see an updated error message reminding the 2G is disabled and potentially disrupting their call connectivity"
+  bug: "300142897"
 }
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