Fix default unit for multipart properties

This commit fixes a regression that wrongly changed the default unit of
multipart properties from bytes to megabytes.

Closes gh-15162

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/MultipartProperties.java

@@ -20,10 +20,8 @@ import javax.servlet.MultipartConfigElement;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.PropertyMapper;
-import org.springframework.boot.convert.DataSizeUnit;
 import org.springframework.boot.web.servlet.MultipartConfigFactory;
 import org.springframework.util.unit.DataSize;
-import org.springframework.util.unit.DataUnit;
 
 /**
  * Properties to be used in configuring a {@link MultipartConfigElement}.
@@ -63,13 +61,11 @@ public class MultipartProperties {
 	/**
 	 * Max file size.
 	 */
-	@DataSizeUnit(DataUnit.MEGABYTES)
 	private DataSize maxFileSize = DataSize.ofMegabytes(1);
 
 	/**
 	 * Max request size.
 	 */
-	@DataSizeUnit(DataUnit.MEGABYTES)
 	private DataSize maxRequestSize = DataSize.ofMegabytes(10);
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/MultipartAutoConfigurationTests.java

@@ -209,6 +209,37 @@ public class MultipartAutoConfigurationTests {
 		assertThat(multipartResolver).hasFieldOrPropertyWithValue("resolveLazily", true);
 	}
 
+	@Test
+	public void configureMultipartProperties() {
+		this.context = new AnnotationConfigServletWebServerApplicationContext();
+		TestPropertyValues
+				.of("spring.servlet.multipart.max-file-size=2048KB",
+						"spring.servlet.multipart.max-request-size=15MB")
+				.applyTo(this.context);
+		this.context.register(WebServerWithNothing.class, BaseConfiguration.class);
+		this.context.refresh();
+		MultipartConfigElement multipartConfigElement = this.context
+				.getBean(MultipartConfigElement.class);
+		assertThat(multipartConfigElement.getMaxFileSize()).isEqualTo(2048 * 1024);
+		assertThat(multipartConfigElement.getMaxRequestSize())
+				.isEqualTo(15 * 1024 * 1024);
+	}
+
+	@Test
+	public void configureMultipartPropertiesWithRawLongValues() {
+		this.context = new AnnotationConfigServletWebServerApplicationContext();
+		TestPropertyValues
+				.of("spring.servlet.multipart.max-file-size=512",
+						"spring.servlet.multipart.max-request-size=2048")
+				.applyTo(this.context);
+		this.context.register(WebServerWithNothing.class, BaseConfiguration.class);
+		this.context.refresh();
+		MultipartConfigElement multipartConfigElement = this.context
+				.getBean(MultipartConfigElement.class);
+		assertThat(multipartConfigElement.getMaxFileSize()).isEqualTo(512);
+		assertThat(multipartConfigElement.getMaxRequestSize()).isEqualTo(2048);
+	}
+
 	private void verify404() throws Exception {
 		HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
 		ClientHttpRequest request = requestFactory.createRequest(new URI(