Remove wrong condition part: there could be irrelevant overrides from Kotlin

compiler/testData/codegen/boxWithJava/collections/irrelevantImplCharSequenceKotlin/J.java

@@ -0,0 +1,7 @@
+public class J {
+    public static class A extends AImpl implements CharSequence {
+        public CharSequence subSequence(int start, int end) {
+            return null;
+        }
+    }
+}