Add equals() funcation for SipPhone.

Since we will use sipuri to match the same phone object.

Change-Id: I582779e51e447bb8d822c105cf0d682651c138d2

telephony/java/com/android/internal/telephony/sip/SipPhone.java

@@ -107,6 +107,10 @@ public class SipPhone extends SipPhoneBase {
         return mProfile.getUriString();
     }
 
+    public boolean equals(SipPhone phone) {
+        return getSipUri().equals(phone.getSipUri()));
+    }
+
     public boolean canTake(Object incomingCall) {
         synchronized (SipPhone.class) {
             if (!(incomingCall instanceof SipAudioCall)) return false;