avoid static imports in Java sample code

[rjayasinghe]

in case this code is copied to an IDE the imports are missing and you have a bit of a challenge to find the right import for the static imports (VS Code Java extension does not support it at all at the moment).

Alternatively we could also use the new 'focus' feature for code blocks and include the static import statements as 'unfocused' but have them included in the clipboard after clicking the copy button.