Test for available() returning 0 when the input is exhausted.

This test typically fails before 3 reps. I've seen it run as many
as 30 reps before it fails. It probably isn't a problem with libcore;
the test also fails on the RI after several reps.

Change-Id: I28cc109898dbfcadd2ed434dd9d590ebd22c9596
http://b/5534202
1 file changed