Added javadoc for special case for Replace annotation.

Change-Id: I11363ab365800b9379121180e6c30a2812447660
Signed-off-by: Matthias Otterbach <Matthias.Otterbach@bsiag.com>
Reviewed-on: https://git.eclipse.org/r/37637
Tested-by: Hudson CI
Reviewed-by: Andi Bur <andi.bur@gmail.com>