Remove java.util references from the common code

libraries/stdlib/test/collections/IterableTests.kt

@@ -17,7 +17,6 @@
 package test.collections
 
 import org.junit.Test
-import java.util.*
 import kotlin.test.*
 
 fun <T> iterableOf(vararg items: T): Iterable<T> = Iterable { items.iterator() }

libraries/stdlib/test/js/JsCollectionsTest.kt

@@ -38,7 +38,7 @@ class JsCollectionsTest {
     }
 
     @test fun arrayListCapacity() {
-        val list = java.util.ArrayList<Any>(20)
+        val list = ArrayList<Any>(20)
         list.ensureCapacity(100)
         list.trimToSize()
         assertTrue(list.isEmpty())