Adjust MAX_FILE_SIZE during test on 32 bit systems

The default MAX_FILE_SIZE of (5 * 2 ** 30 + 2) exceeds the
capacity of an int on 32 bit systems; adjust this default
down to (2 ** 30 + 2) if the default exceeds the maxsize of
an int on the platform running the tests.

Closes-Bug: #1378810

Change-Id: Iafa2ce90ceb2de4e968ad48580270c8c572a9c9c
Merge "Adjust MAX_FILE_SIZE during test on 32 bit systems"