[RenderScript] Update the documentation of Script.LaunchOptions

Bug: 26916665

  - Add description of the endArg.
  - Update the example.
  - Update the incorrect description.

Change-Id: I89fda42dc6a8bdbf3766916d84f7937275f96a42
(cherry picked from commit ec7aaf761b70596614cb832939c881eea6e2941f)
1 file changed