Fix large file download failure issue

The root cause is int overflow as integer can only hold size
Integer.MAX_VALUE = 0x7FFFFFFF. It is about 2G. So, when a file size
is greater than 2G, it throws a "NumberFormatException", and then
mark this download "unsuccessfully".
The progress bar in notification for the large file downloading was
not correct either. The total file size was converted from long to
int value when in builder.setProgress().

Change-Id: Ib038860e26cf8cade2c423403585c207f8b8979b
2 files changed