KTIJ-585 [Gradle Runner]: main() cannot be launched from AS 4.1

Android gradle-project model differs from what we have for pure Java
and MPP. It's the reason why application classpath cannot be collected
correctly.
Until universal solution is provided delegation to gradle is put under
the registry flag. If disable platform runner is used as before.

idea/idea-gradle/src/org/jetbrains/kotlin/idea/gradle/execution/KotlinGradleAppEnvProvider.kt

@@ -33,6 +33,7 @@ import com.intellij.openapi.projectRoots.ex.JavaSdkUtil
 import com.intellij.openapi.roots.ModuleRootManager
 import com.intellij.openapi.roots.ProjectFileIndex
 import com.intellij.openapi.util.io.FileUtil
+import com.intellij.openapi.util.registry.Registry
 import com.intellij.openapi.util.text.StringUtil
 import com.intellij.psi.PsiClass
 import com.intellij.psi.PsiJavaModule
@@ -50,7 +51,10 @@ import org.jetbrains.plugins.gradle.util.GradleConstants
  */
 class KotlinGradleAppEnvProvider : GradleExecutionEnvironmentProvider {
 
-    override fun isApplicable(task: ExecuteRunConfigurationTask): Boolean = task.runProfile is KotlinRunConfiguration
+    override fun isApplicable(task: ExecuteRunConfigurationTask): Boolean {
+        val enabled = Registry.`is`("kotlin.gradle-run.enabled", false)
+        return enabled && task.runProfile is KotlinRunConfiguration
+    }
 
     override fun createExecutionEnvironment(
         project: Project, executeRunConfigurationTask: ExecuteRunConfigurationTask, executor: Executor?

idea/resources/META-INF/extensions/ide.xml

@@ -135,6 +135,11 @@
                      defaultValue="false"
                      restartRequired="false"/>
 
+        <registryKey key="kotlin.gradle-run.enabled"
+                     description="Enable delegation of app running to gradle"
+                     defaultValue="false"
+                     restartRequired="false"/>
+
         <fileEditorProvider implementation="org.jetbrains.kotlin.idea.scratch.ui.KtScratchFileEditorProvider"/>
 
         <jbProtocolCommand implementation="org.jetbrains.kotlin.tools.projectWizard.wizard.OpenNewProjectWizardProtocolCommand"/>