Fix spring.quartz.jdbc.initialize-schema value

Use enum value from DataSourceInitializationMode instead of Boolean.

Closes gh-11433

spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -5555,7 +5555,7 @@ following example:
 
 [source,properties,indent=0]
 ----
-	spring.quartz.jdbc.initialize-schema=true
+	spring.quartz.jdbc.initialize-schema=always
 ----
 
 NOTE: By default, the database is detected and initialized by using the standard scripts