New J2K: convert vararg type parameter Java length call to Kotlin size call

nj2k/testData/newJ2k/varArg/varargLengthAccess.java

@@ -0,0 +1,4 @@
+//method
+int nya(Object... objs) {
+    return objs.length;
+}

nj2k/testData/newJ2k/varArg/varargLengthAccess.kt

@@ -0,0 +1,3 @@
+fun nya(vararg objs: Any?): Int {
+    return objs.size
+}