Add extra key for call attributes.

Add an extra key used internally with call attributes when setting up a
call.

Test: Manual testing.
Bug: 277232336
Merged-In: Ic8b5d57df88cf9c1d8a82a11ad4934ed4ef5fd78
Change-Id: Ic8b5d57df88cf9c1d8a82a11ad4934ed4ef5fd78
diff --git a/telecomm/java/android/telecom/CallAttributes.java b/telecomm/java/android/telecom/CallAttributes.java
index 52ff90f..b1a7d81 100644
--- a/telecomm/java/android/telecom/CallAttributes.java
+++ b/telecomm/java/android/telecom/CallAttributes.java
@@ -59,6 +59,9 @@
     public static final String CALL_CAPABILITIES_KEY = "TelecomCapabilities";
 
     /** @hide **/
+    public static final String DISPLAY_NAME_KEY = "DisplayName";
+
+    /** @hide **/
     public static final String CALLER_PID_KEY = "CallerPid";
 
     /** @hide **/