Make common ArrayList declaration not open and implementing RandomAccess

libraries/stdlib/common/src/kotlin/collections/ArrayList.kt

@@ -16,7 +16,7 @@
 
 package kotlin.collections
 
-expect open class ArrayList<E> : MutableList<E> {
+expect class ArrayList<E> : MutableList<E>, RandomAccess {
     constructor()
     constructor(initialCapacity: Int)
     constructor(elements: Collection<E>)

libraries/stdlib/test/collections/CollectionTest.kt

@@ -901,7 +901,7 @@ class CollectionTest {
     }
 
     @Test fun randomAccess() {
-        assertTrue(arrayListOf(1) is RandomAccess, "ArrayList is RandomAccess")
+        assertStaticAndRuntimeTypeIs<RandomAccess>(arrayListOf(1))
         assertTrue(listOf(1, 2) is RandomAccess, "Default read-only list implementation is RandomAccess")
         assertTrue(listOf(1) is RandomAccess, "Default singleton list is RandomAccess")
         assertTrue(emptyList<Int>() is RandomAccess, "Empty list is RandomAccess")