KT-7443 Inspection + intention to replace assert (x != null) with "!!" or elvis

#KT-7443 Fixed

j2k/testData/fileOrElement/assertStatement/assertNotNull.kt

@@ -0,0 +1,11 @@
+internal abstract class C {
+    fun foo() {
+        val s1 = f()!!
+
+        val s2 = g() ?: error("g should not return null")
+        val h = s2.hashCode()
+    }
+
+    internal abstract fun f()
+    internal abstract fun g()
+}