Fix Integer conversion in getProgress() method

See gh-44718

Signed-off-by: youngjin_dev <qazkyj0310@gmail.com>

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/TotalProgressListener.java

@@ -120,7 +120,7 @@ public abstract class TotalProgressListener<E extends ImageProgressUpdateEvent>
 		}
 
 		int getProgress() {
-			return withinPercentageBounds((this.progressByStatus.values().stream().mapToInt(Integer::valueOf).sum())
+			return withinPercentageBounds((this.progressByStatus.values().stream().mapToInt(Integer::intValue).sum())
 					/ this.progressByStatus.size());
 		}