Address Call Streaming API review comments.

1. Make CallStreamingService and StreamingCall SystemApi and hide
2. Add android.permission.BIND_STREAMING_SERVICE
3. Change StreamingCall#DisplayName to CharSequence
4. Hide StreamingCall constructor
5. Fix CallControl#startCallStreaming doc

Bug: 265304561
Test: build; add cts
API-Coverage-Bug: 268061643
Change-Id: I29771cfbf60553eb8325e40b2cd11c5828a445e4
diff --git a/telecomm/java/android/telecom/CallControl.java b/telecomm/java/android/telecom/CallControl.java
index f3c91f6..2135e27 100644
--- a/telecomm/java/android/telecom/CallControl.java
+++ b/telecomm/java/android/telecom/CallControl.java
@@ -197,10 +197,10 @@
      *                 of the requested operation.
      *
      *                 {@link OutcomeReceiver#onResult} will be called if Telecom has successfully
-     *                 rejected the incoming call.
+     *                 started the call streaming.
      *
      *                 {@link OutcomeReceiver#onError} will be called if Telecom has failed to
-     *                 reject the incoming call.  A {@link CallException} will be passed that
+     *                 start the call streaming. A {@link CallException} will be passed that
      *                 details why the operation failed.
      */
     public void startCallStreaming(@CallbackExecutor @NonNull Executor executor,