Merge pull request #21490 from dsyer

* gh-21490:
  Polish `Add gradle build image command line example`
  Add gradle build image command line example

Closes gh-21490

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/asciidoc/packaging-oci-image.adoc

@@ -96,6 +96,13 @@ include::../gradle/packaging/boot-build-image-builder.gradle.kts[tags=builder]
 
 This configuration will use a builder image with the name `mine/java-cnb-builder` and the tag `latest`.
 
+The builder can be specified on the command line as well, as shown in this example:
+
+[indent=0]
+----
+$ gradle bootBuildImage --builder=mine/java-cnb-builder
+----
+
 
 
 [[build-image-example-builder-configuration]]
@@ -151,4 +158,11 @@ include::../gradle/packaging/boot-build-image-name.gradle.kts[tags=image-name]
 ----
 
 Note that this configuration does not provide an explicit tag so `latest` is used.
-It is possible to specify a tag as well, either using `${project.version}`, any property available in the build or a hardcoded version.
\ No newline at end of file
+It is possible to specify a tag as well, either using `${project.version}`, any property available in the build or a hardcoded version.
+
+The image name can be specified on the command line as well, as shown in this example:
+
+[indent=0]
+----
+$ gradle bootBuildImage --imageName=example.com/library/my-app:v1
+----