Hide calllog entries for unregistered phone accounts

Cherry-picked from master

Change-Id: If1f873dd41c973442fa7a24020e56d13b7b5ad2c
diff --git a/telecomm/java/android/telecom/TelecomManager.java b/telecomm/java/android/telecom/TelecomManager.java
index 6c5f1c6..8be3e66 100644
--- a/telecomm/java/android/telecom/TelecomManager.java
+++ b/telecomm/java/android/telecom/TelecomManager.java
@@ -92,6 +92,15 @@
             "android.telecom.action.CHANGE_PHONE_ACCOUNTS";
 
     /**
+     * The {@link android.content.Intent} action used indicate that a new phone account was
+     * just registered.
+     * @hide
+     */
+    @SystemApi
+    public static final String ACTION_PHONE_ACCOUNT_REGISTERED =
+            "android.telecom.action.PHONE_ACCOUNT_REGISTERED";
+
+    /**
      * Optional extra for {@link android.content.Intent#ACTION_CALL} containing a boolean that
      * determines whether the speakerphone should be automatically turned on for an outgoing call.
      */