Misc: Extract "KotlinSdkAdded" test to separate test case

This is needed due to application being initialized only once per test case,
while Kotlin SDK is configured during PluginStartupComponent initialization

idea/tests/org/jetbrains/kotlin/idea/configuration/AutoConfigureKotlinSdkOnStartupTest.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.configuration
+
+import com.intellij.openapi.projectRoots.ProjectJdkTable
+import org.jetbrains.kotlin.idea.framework.KotlinSdkType
+import org.junit.Assert
+
+// Do not add new tests here since application is initialized only once
+class AutoConfigureKotlinSdkOnStartupTest : ConfigureKotlinInTempDirTest() {
+    fun testKotlinSdkAdded() {
+        Assert.assertTrue(ProjectJdkTable.getInstance().allJdks.any { it.sdkType is KotlinSdkType })
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/configuration/ConfigureKotlinInTempDirTest.kt

@@ -18,20 +18,18 @@ package org.jetbrains.kotlin.idea.configuration
 
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.application.impl.ApplicationImpl
-import com.intellij.openapi.projectRoots.ProjectJdkTable
 import com.intellij.openapi.util.io.FileUtil
 import org.jetbrains.kotlin.config.ApiVersion
 import org.jetbrains.kotlin.config.KotlinFacetSettingsProvider
 import org.jetbrains.kotlin.config.LanguageVersion
 import org.jetbrains.kotlin.idea.compiler.configuration.KotlinCommonCompilerArgumentsHolder
-import org.jetbrains.kotlin.idea.framework.KotlinSdkType
 import org.jetbrains.kotlin.idea.project.getLanguageVersionSettings
 import org.jetbrains.kotlin.idea.project.languageVersionSettings
 import org.junit.Assert
 import java.io.File
 import java.io.IOException
 
-class ConfigureKotlinInTempDirTest : AbstractConfigureKotlinTest() {
+open class ConfigureKotlinInTempDirTest : AbstractConfigureKotlinTest() {
     @Throws(IOException::class)
     override fun getIprFile(): File {
         val tempDir = FileUtil.generateRandomTemporaryPath()
@@ -130,8 +128,4 @@ class ConfigureKotlinInTempDirTest : AbstractConfigureKotlinTest() {
         val settings = myProject.getLanguageVersionSettings()
         Assert.assertEquals(ApiVersion.KOTLIN_1_1, settings.apiVersion)
     }
-
-    fun testKotlinSdkAdded() {
-        Assert.assertTrue(ProjectJdkTable.getInstance().allJdks.any { it.sdkType is KotlinSdkType })
-    }
 }