doc: Add note to Context.bindService()

Per email from Dianne H, even if bindService() returns false, the
client should still call unbindService() to release the connection.

Doc is staged to:

http://go/dac-stage/reference/android/content/Context.html#bindService(android.content.Intent,%20android.content.ServiceConnection,%20int)

Bug: 37092557
Test: make ds-docs
Change-Id: I5849aaccec933ee7660b31241e4d8eff9ee1ef72

core/java/android/content/Context.java

@@ -2745,7 +2745,8 @@ public abstract class Context {
      *          {@link #BIND_WAIVE_PRIORITY}.
      * @return If you have successfully bound to the service, {@code true} is returned;
      *         {@code false} is returned if the connection is not made so you will not
-     *         receive the service object.
+     *         receive the service object. However, you should still call
+     *         {@link #unbindService} to release the connection.
      *
      * @throws SecurityException If the caller does not have permission to access the service
      * or the service can not be found.