fix: default encoding for test cases on windows

[nx-eric-jarosch]

new String(byte[]) uses Charset.defaultCharset() as the encoding. This only works on machines where the default charset is UTF-8, because all of the test.properties files are encoded using UTF-8.

Consequently, 21 tests fail on windows, because here the default charset is windows-1252, while the test.properties files are still encoded using UTF-8, causing a mismatch to be detected by the tests.

The fix is to explicitly use the correct encoding.

Additional references

Source code for `new String(byte[])` and javadoc for `Charset.defaultCharset()`:

    /**
     * Constructs a new {@code String} by decoding the specified array of bytes
     * using the {@link Charset#defaultCharset() default charset}. The length
     * of the new {@code String} is a function of the charset, and hence may not
     * be equal to the length of the byte array.
     *
     * <p> The behavior of this constructor when the given bytes are not valid
     * in the default charset is unspecified.  The {@link
     * java.nio.charset.CharsetDecoder} class should be used when more control
     * over the decoding process is required.
     *
     * <p> The contents of the string are unspecified if the byte array
     * is modified during string construction.
     *
     * @param  bytes
     *         The bytes to be decoded into characters
     *
     * @since  1.1
     */
    public String(byte[] bytes) {
        this(Charset.defaultCharset(), bytes, 0, bytes.length);
    }

    /**
     * Returns the default charset of this Java virtual machine.
     *
     * <p> The default charset is {@code UTF-8}, unless changed in an
     * implementation specific manner.
     *
     * @implNote An implementation may override the default charset with
     * the system property {@code file.encoding} on the command line. If the
     * value is {@code COMPAT}, the default charset is derived from
     * the {@code native.encoding} system property, which typically depends
     * upon the locale and charset of the underlying operating system.
     *
     * @return  A charset object for the default charset
     * @see System##file.encoding file.encoding
     * @see System##native.encoding native.encoding
     *
     * @since 1.5
     */
    public static Charset defaultCharset()

[quintesse]

This was only for tests, so really a non-risk merge. Thanks!