Move `java/preprocessor` to Gradle #175

Job	Run time
Test Processing	1m 20s
(linux/aarch64) Create Processing Build	7m 10s
(linux/x64) Create Processing Build	8m 47s
(windows/x64) Create Processing Build	8m 22s
(macos/x64) Create Processing Build	7m 27s
(macos/aarch64) Create Processing Build	3m 50s
	36m 56s

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