Polish "Use JsonMapper instead of ObjectMapper where feasible"

See gh-47503

Author: snicoll

buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/json/MappedObject.java

@@ -204,7 +204,7 @@ protected interface ContentReader<C> {
 
 		/**
 		 * Read JSON content as a {@link JsonNode}.
-		 * @param jsonMapper the source json mapper
+		 * @param jsonMapper the source JSON mapper
 		 * @param content the content to read
 		 * @return a {@link JsonNode}
 		 * @throws IOException on IO error

core/spring-boot/src/main/java/org/springframework/boot/json/JacksonJsonParser.java

@@ -40,7 +40,7 @@ public class JacksonJsonParser extends AbstractJsonParser {
 
 	/**
 	 * Creates an instance with the specified {@link JsonMapper}.
-	 * @param jsonMapper the json mapper to use
+	 * @param jsonMapper the JSON mapper to use
 	 */
 	public JacksonJsonParser(JsonMapper jsonMapper) {
 		this.jsonMapper = jsonMapper;