Add the relevant flag to guard call setting security fixes.

This CL adds the flag that will be used to guard the call settings security vulnerability fixes in CdmaCallOptions and GsmUmtsCallOptions.

Test: manual
Bug: 309655251
Change-Id: I83e240b711162ec4adfb31586813575d3966f2c3
diff --git a/flags/misc.aconfig b/flags/misc.aconfig
index 87acccc..e9e3169 100644
--- a/flags/misc.aconfig
+++ b/flags/misc.aconfig
@@ -20,4 +20,11 @@
   namespace: "telephony"
   description: "Enable system api isWpsCallNumber. Its an utility api to check if the dialed number is for Wireless Priority Service call."
   bug: "304272356"
+}
+
+flag {
+  name: "ensure_access_to_call_settings_is_restricted"
+  namespace: "telephony"
+  description: "Check if access to mobile network configs restricted before displaying call options"
+  bug: "309655251"
 }
\ No newline at end of file