Add intent broadcast when a PhoneAccount is enabled or disabled. (3/3)

- Handling intent in SipAccountRegistry and disabling/enabling Sip
accounts as required.
- Changing SipSettings so that disabled Sip account do not show as
"receiving calls" when they're disabled.

Bug: 17408536
Change-Id: Ia74c8c884719e8c399dfe6941980f467e00ac87b
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index dd9b06d..9bc9a58 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -499,6 +499,8 @@
                 <action android:name="com.android.phone.SIP_INCOMING_CALL" />
                 <action android:name="com.android.phone.SIP_REMOVE_PHONE" />
                 <action android:name="com.android.phone.SIP_CALL_OPTION_CHANGED" />
+                <action android:name="android.telecom.action.PHONE_ACCOUNT_ENABLED" />
+                <action android:name="android.telecom.action.PHONE_ACCOUNT_DISABLED" />
             </intent-filter>
         </receiver>