ErrorProne warns [1] about implicit use of the platform default charset,
which can result in differing behaviour between JVM executions or
incorrect behavior if the encoding of the data source doesn't match
expectations.
[1] http://errorprone.info/bugpattern/DefaultCharset
Change-Id: I0fd489d352170339c3867355cd24324dfdbd4b59
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>