Add smoke test for greeting plugin used in the GE build

subprojects/smoke-test/src/smokeTest/groovy/org/gradle/smoketests/GreetingSamplePluginSmokeTest.groovy

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.gradle.smoketests
+
+import org.gradle.util.GradleVersion
+
+import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
+
+// https://plugins.gradle.org/plugin/org.samples.greeting
+// Plugin is used by the GE build.
+class GreetingSamplePluginSmokeTest extends AbstractSmokeTest {
+    def 'greeting plugin'() {
+        given:
+        buildFile << """
+            plugins {
+                id 'org.samples.greeting' version '1.0'
+            }
+        """.stripIndent()
+
+        when:
+        def result = runner('hello').forwardOutput().build()
+
+        then:
+        result.task(':hello').outcome == SUCCESS
+
+        expectDeprecationWarnings(
+            result,
+            "Property 'greeting' is not annotated with an input or output annotation. " +
+                "This behaviour has been deprecated and is scheduled to be removed in Gradle 7.0. " +
+                "Execution optimizations are disabled due to the failed validation. " +
+                "See https://docs.gradle.org/${GradleVersion.current().version}/userguide/more_about_tasks.html#sec:up_to_date_checks for more details."
+        )
+    }
+}