Add feature flag to prevent hangup during call merge

Bug: 317070933
Flag:  com.android.internal.telephony.flags.prevent_hangup_during_call_merge
Test: build pass
Change-Id: I543982ce2eff45b5c45858cdc5c4d50fd81b8952
diff --git a/flags/ims.aconfig b/flags/ims.aconfig
index 4eff505..1056ea3 100644
--- a/flags/ims.aconfig
+++ b/flags/ims.aconfig
@@ -115,3 +115,14 @@
         purpose: PURPOSE_BUGFIX
     }
 }
+
+# OWNER=joonhunshin TARGET=24Q4
+flag {
+    name: "prevent_hangup_during_call_merge"
+    namespace: "telephony"
+    description: "This flag prevents hangup call during call merge"
+    bug:"317070933"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
+}