Android extensions: Do not cache ViewStub widgets, do not cast it automatically

plugins/android-compiler-plugin/testData/descriptors/viewStub/res/layout/test.xml

@@ -0,0 +1,11 @@
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+             xmlns:tools="http://schemas.android.com/tools"
+             android:layout_width="match_parent"
+             android:layout_height="match_parent" >
+
+    <ViewStub
+        android:id="@+id/stub"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content" />
+
+</FrameLayout>

plugins/android-compiler-plugin/testData/descriptors/viewStub/result.txt

@@ -0,0 +1,35 @@
+kotlinx
+
+
+kotlinx.android
+
+
+kotlinx.android.synthetic
+
+    public fun android.app.Activity.clearFindViewByIdCache(): kotlin.Unit
+    public fun android.app.Fragment.clearFindViewByIdCache(): kotlin.Unit
+
+
+kotlinx.android.synthetic.main
+
+
+kotlinx.android.synthetic.main.test
+
+    public val android.app.Activity.stub: android.view.View!
+    public val android.app.Fragment.stub: android.view.View!
+
+
+kotlinx.android.synthetic.main.test.view
+
+    public val android.view.View.stub: android.view.View!
+
+
+kotlinx.android.synthetic.test
+
+    public val android.app.Activity.stub: android.view.View!
+    public val android.app.Fragment.stub: android.view.View!
+
+
+kotlinx.android.synthetic.test.view
+
+    public val android.view.View.stub: android.view.View!