fix(java-spring): add missing imports for converter (#23325) #1159

Job	Run time
Build with JDK17 (samples/client/petstore/java-helidon-client/v3/mp/)	1m 1s
Build with JDK17 (samples/client/petstore/spring-http-interface-useHttpServiceProxyFactoryInterfa...	42s
Build with JDK17 (samples/client/petstore/spring-http-interface-reactive)	58s
Build with JDK17 (samples/client/petstore/java/microprofile-rest-client-outer-enum)	1m 11s
Build with JDK17 (samples/client/petstore/spring-http-interface-noResponseEntity)	42s
Build with JDK17 (samples/client/petstore/spring-http-interface)	39s
Build with JDK17 (samples/openapi3/server/petstore/springboot-3)	51s
Build with JDK17 (samples/server/petstore/springboot-x-implements-skip)	49s
Build with JDK17 (samples/client/petstore/spring-http-interface-reactive-noResponseEntity)	47s
Build with JDK17 (samples/server/petstore/java-helidon-server/v3/mp/)	1m 19s
Build with JDK17 (samples/openapi3/client/petstore/spring-cloud-3)	50s
Build with JDK17 (samples/client/petstore/java/webclient-jakarta)	45s
Build with JDK17 (samples/server/petstore/java-helidon-server/v3/se)	1m 7s
Build with JDK17 (samples/openapi3/server/petstore/springboot-3-include-http-request-context)	48s
Build with JDK17 (samples/client/petstore/java-helidon-client/v3/se)	46s
Build with JDK17 (samples/server/petstore/java-camel/)	56s
	14m 11s

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