Revert "@hide ConnectionService APIs."

This reverts commit 86935c406e4a8bb0e2ad871b51009f3603df9e87.

telecomm/java/android/telecom/ConnectionRequest.java

@@ -16,7 +16,6 @@
 
 package android.telecom;
 
-import android.annotation.SystemApi;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Parcel;
@@ -25,9 +24,7 @@ import android.os.Parcelable;
 /**
  * Simple data container encapsulating a request to some entity to
  * create a new {@link Connection}.
- * @hide
  */
-@SystemApi
 public final class ConnectionRequest implements Parcelable {
 
     // TODO: Token to limit recursive invocations