Always initialize Gradle User Home with init script

The generated gradle.properties file and init script are not cached,
so need to be generated even when restoring from cache.

src/cache-gradle-user-home.ts

@@ -7,7 +7,6 @@ import * as exec from '@actions/exec'
 
 import {AbstractCache, CacheEntryListener, CacheListener} from './cache-base'
 import {getCacheKeyPrefix, hashFileNames, tryDelete} from './cache-utils'
-import {writeBuildScanCaptureInitScript} from './build-scan-capture'
 
 const META_FILE_DIR = '.gradle-build-action'
 
@@ -23,20 +22,9 @@ export class GradleUserHomeCache extends AbstractCache {
         this.gradleUserHome = this.determineGradleUserHome(rootDir)
     }
 
-    async initializeState(): Promise<void> {
-        this.initializeGradleUserHome(this.gradleUserHome)
-    }
-
-    private initializeGradleUserHome(gradleUserHome: string): void {
-        fs.mkdirSync(gradleUserHome, {recursive: true})
-
-        const propertiesFile = path.resolve(gradleUserHome, 'gradle.properties')
-        this.debug(`Initializing gradle.properties to disable daemon: ${propertiesFile}`)
-        fs.writeFileSync(propertiesFile, 'org.gradle.daemon=false')
-
-        const initScript = path.resolve(gradleUserHome, 'init.gradle')
-        this.debug(`Adding init script to capture build scans: ${initScript}`)
-        writeBuildScanCaptureInitScript(initScript)
+    init(): void {
+        this.debug(`Initializing Gradle User Home with properties and init script: ${this.gradleUserHome}`)
+        initializeGradleUserHome(this.gradleUserHome)
     }
 
     async afterRestore(listener: CacheListener): Promise<void> {
@@ -271,3 +259,49 @@ export class GradleUserHomeCache extends AbstractCache {
         core.info('-----------------------')
     }
 }
+
+function initializeGradleUserHome(gradleUserHome: string): void {
+    fs.mkdirSync(gradleUserHome, {recursive: true})
+
+    const propertiesFile = path.resolve(gradleUserHome, 'gradle.properties')
+    fs.writeFileSync(propertiesFile, 'org.gradle.daemon=false')
+
+    const initScript = path.resolve(gradleUserHome, 'init.gradle')
+    fs.writeFileSync(
+        initScript,
+        `
+import org.gradle.util.GradleVersion
+
+// Don't run against the included builds (if the main build has any).
+def isTopLevelBuild = gradle.getParent() == null
+if (isTopLevelBuild) {
+    def version = GradleVersion.current().baseVersion
+    def atLeastGradle4 = version >= GradleVersion.version("4.0")
+    def atLeastGradle6 = version >= GradleVersion.version("6.0")
+
+    if (atLeastGradle6) {
+        settingsEvaluated { settings ->
+            if (settings.pluginManager.hasPlugin("com.gradle.enterprise")) {
+                registerCallbacks(settings.extensions["gradleEnterprise"].buildScan, settings.rootProject.name)
+            }
+        }
+    } else if (atLeastGradle4) {
+        projectsEvaluated { gradle ->
+            if (gradle.rootProject.pluginManager.hasPlugin("com.gradle.build-scan")) {
+                registerCallbacks(gradle.rootProject.extensions["buildScan"], gradle.rootProject.name)
+            }
+        }
+    }
+}
+
+def registerCallbacks(buildScanExtension, rootProjectName) {
+    buildScanExtension.with {
+        def scanFile = new File("gradle-build-scan.txt")
+        buildScanPublished { buildScan ->
+            scanFile.text = buildScan.buildScanUri
+        }
+    }
+}
+`
+    )
+}