Escape '{' in StringEscapeUtils.ESCAPE_XSI

[dxbjavid]

StringEscapeUtils.ESCAPE_XSI backslash-escapes shell metacharacters but leaves { alone, so bash and zsh still apply brace expansion to the escaped value. escapeXSI("{report.txt,-delete}") comes back unchanged, and bash -c "find . -name " + escaped runs find . -name report.txt -delete: one escaped value becomes two arguments, and the second is an option chosen by whoever supplied the input.

Repro, before the fix: bash -c "printf '<%s>\n' " + escapeXSI("{report.txt,-delete}") prints <report.txt> and <-delete>. After the fix it prints one argument, <{report.txt,-delete}>. Escaping { alone stops the expansion, the same way the map escapes [ but not ]. UNESCAPE_XSI already round-trips \{.

The new assertions in StringEscapeUtilsTest#testEscapeXSI fail without the main change and pass with it. The default mvn build is green.

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