Fetch own username from the whoami endpoint.

libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/WhoAmIResponse.java

@@ -12,6 +12,9 @@ public class WhoAmIResponse {
   @JsonProperty
   public String number;
 
+  @JsonProperty
+  public String username;
+
   public String getAci() {
     return uuid;
   }
@@ -23,4 +26,8 @@ public class WhoAmIResponse {
   public String getNumber() {
     return number;
   }
+
+  public String getUsername() {
+    return username;
+  }
 }