Always append to files, handle end of stream.

Fix bug where resumed downloads wouldn't open in append mode. Handle
end of stream exceptions from URLConnection as special-case for now
to keep tests passing.

Move stream creation outside of DrmOutputStream, and always fsync()
before closing files. Treat HTTP header errors as retryable. Add
explicit state checks to redirection tests.

Change-Id: I19d007284f6bfbffaac93859fe47cd98b79a59c4
2 files changed