Disable internal mode in AS 3.3 and AS 3.4 to avoid using core class loader

Core class loader doesn't include Kotlin plugin dependencies and Kotlin
plugin becomes unusable (for example Gradle sync always fail).

https://issuetracker.google.com/issues/119250571

buildSrc/src/main/kotlin/intellijDependencies.kt

@@ -129,12 +129,16 @@ fun Project.runIdeTask(name: String, ideaPluginDir: File, ideaSandboxDir: File,
 
         workingDir = File(intellijRootDir(), "bin")
 
+        // https://issuetracker.google.com/issues/119250571
+        var isInternal = true
+        Ide.AS33.orHigher { isInternal = false }
+
         jvmArgs(
             "-Xmx1250m",
             "-XX:ReservedCodeCacheSize=240m",
             "-XX:+HeapDumpOnOutOfMemoryError",
             "-ea",
-            "-Didea.is.internal=true",
+            "-Didea.is.internal=$isInternal",
             "-Didea.debug.mode=true",
             "-Didea.system.path=$ideaSandboxDir",
             "-Didea.config.path=$ideaSandboxConfigDir",