Remove explicit 8192 arguments to BufferedReader and friends.

These were clearly added just to shut up our own warning, and are now
unnecessary and misleading to future maintainers.

There's one barely-related change: InputStreamReader and OutputStreamWriter
are very similar, and this patch makes them more similar, and adds a few
missing modifiers from their fields.

Change-Id: I959011f914ff215e92bbfa41c1bac66465803685
21 files changed