Fix emergency callback number not shown for incoming calls.

- When building connection capabilities, set
CAPABILITY_SHOW_CALLBACK_NUMBER when the phone is in ECM mode.

Bug: 18689292
Change-Id: Ic30baa38950f135bf7cc5adaeb59dbd23d495e21
diff --git a/src/com/android/services/telephony/TelephonyConnection.java b/src/com/android/services/telephony/TelephonyConnection.java
index 8499263..a9e0386 100644
--- a/src/com/android/services/telephony/TelephonyConnection.java
+++ b/src/com/android/services/telephony/TelephonyConnection.java
@@ -442,6 +442,13 @@
                 callCapabilities |= CAPABILITY_HOLD;
             }
         }
+
+        // If the phone is in ECM mode, mark the call to indicate that the callback number should be
+        // shown.
+        Phone phone = getPhone();
+        if (phone != null && phone.isInEcm()) {
+            callCapabilities |= CAPABILITY_SHOW_CALLBACK_NUMBER;
+        }
         return callCapabilities;
     }