Mms: Clean up delivery report dialog.

Instead of launching another activity just to show the delivery report,
mimic how showMessageDetails works instead, using AlertDialog.Builder.
This ports the dialog over to Holo as well.

Change-Id: Ia7ee549fe7ed9770a70482a042ebbc4bc12bab21
Signed-off-by: angelsl <hidingfromhidden@gmail.com>