Revert^2 "Mark @FlaggedApi flags as exported"

5df163225b3f98912522994930804ba77bd80e62

Change-Id: I3d54d5235398831aec42b06e52300fa1adb515e2
diff --git a/flags/calling.aconfig b/flags/calling.aconfig
index 906abfc..65cfbaf 100644
--- a/flags/calling.aconfig
+++ b/flags/calling.aconfig
@@ -69,4 +69,5 @@
     namespace: "telephony"
     description: "Used to notify the emergency callback mode for call/SMS to other applications."
     bug:"359064059"
+    is_exported: true
 }