KAPT: Skip importing java.lang.System in the stubs

This fixes KT-43117

plugins/kapt3/kapt3-compiler/testData/converter/lazyProperty.txt

@@ -1,5 +1,3 @@
-import java.lang.System;
-
 @kotlin.Metadata()
 public final class Foo {
     private final kotlin.Lazy foo$delegate = null;
@@ -31,8 +29,6 @@ public final class Foo {
 ////////////////////
 
 
-import java.lang.System;
-
 @kotlin.Metadata()
 public abstract interface GenericIntf<T extends java.lang.Object> {
 }
@@ -40,8 +36,6 @@ public abstract interface GenericIntf<T extends java.lang.Object> {
 ////////////////////
 
 
-import java.lang.System;
-
 @kotlin.Metadata()
 public abstract interface Intf {
 }