[Java] Replace `if` with `?` in Generated `toIndentedString`-methods #1136

Job	Run time
Build with JDK17 (samples/client/petstore/java-helidon-client/v3/se)	53s
Build with JDK17 (samples/client/petstore/spring-http-interface-reactive)	51s
Build with JDK17 (samples/openapi3/client/petstore/spring-cloud-3)	52s
Build with JDK17 (samples/client/petstore/java-helidon-client/v3/mp/)	46s
Build with JDK17 (samples/client/petstore/spring-http-interface-reactive-noResponseEntity)	48s
Build with JDK17 (samples/client/petstore/java/webclient-jakarta)	42s
Build with JDK17 (samples/openapi3/server/petstore/springboot-3-include-http-request-context)	49s
Build with JDK17 (samples/server/petstore/springboot-x-implements-skip)	1m 4s
Build with JDK17 (samples/client/petstore/spring-http-interface)	48s
Build with JDK17 (samples/server/petstore/java-helidon-server/v3/se)	46s
Build with JDK17 (samples/client/petstore/spring-http-interface-noResponseEntity)	43s
Build with JDK17 (samples/openapi3/server/petstore/springboot-3)	50s
Build with JDK17 (samples/server/petstore/java-camel/)	58s
Build with JDK17 (samples/client/petstore/java/microprofile-rest-client-outer-enum)	56s
Build with JDK17 (samples/server/petstore/java-helidon-server/v3/mp/)	49s
	12m 35s

Provide feedback