Add option to customize cache volume names when building an image

This commit adds configuration to the Maven and Gradle plugins to
allow specifying the names of build and launch cache volumes provided
to the CNB builder.

See gh-28292

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

@@ -181,6 +181,11 @@ The value supplied will be passed unvalidated to Docker when creating the builde
 | A list of one or more additional tags to apply to the generated image.
 |
 
+| `cacheVolumeNames`
+|
+| Cache volume names that should be used by the builder instead of generating random names.
+|
+
 |===
 
 NOTE: The plugin detects the target Java compatibility of the project using the JavaPlugin's `targetCompatibility` property.

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-cacheVolumeNames.gradle

@@ -0,0 +1,23 @@
+plugins {
+	id 'java'
+	id 'org.springframework.boot' version '{gradle-project-version}'
+}
+
+bootJar {
+	mainClass = 'com.example.ExampleApplication'
+}
+
+// tag::cacheVolumeNames[]
+bootBuildImage {
+    cacheVolumeNames = [
+        "build": "example-build-cachevol",
+        "launch": "example-launch-cachevol"
+    ]
+}
+// end::cacheVolumeNames[]
+
+task bootBuildImageCacheVolumeNames {
+	doFirst {
+		bootBuildImage.cacheVolumeNames.each { type, name -> println "$type=$name" }
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-cacheVolumeNames.gradle.kts

@@ -0,0 +1,21 @@
+import org.springframework.boot.gradle.tasks.bundling.BootBuildImage
+
+plugins {
+	java
+	id("org.springframework.boot") version "{gradle-project-version}"
+}
+
+// tag::cacheVolumeNames[]
+tasks.getByName<BootBuildImage>("bootBuildImage") {
+	cacheVolumeNames = mapOf("build" to "example-build-cachevol",
+						"launch" to "example-launch-cachevol")
+}
+// end::cacheVolumeNames[]
+
+tasks.register("bootBuildImageEnvironment") {
+	doFirst {
+		for((type, name) in tasks.getByName<BootBuildImage>("bootBuildImage").cacheVolumeNames) {
+			print(type + "=" + name)
+		}
+	}
+}