Write nullability annotations on extension receiver parameters

#KT-5429 Fixed

idea/testData/refactoring/changeSignature/AddPropertyReceiverAfter.1.java

@@ -1,15 +1,17 @@
+<caret>import org.jetbrains.annotations.NotNull;
+
 import java.lang.Override;
 
 public class J extends A {
     private int p;
 
     @Override
-    public int getP(String receiver) {
+    public int getP(@NotNull String receiver) {
         return p;
     }
 
     @Override
-    public void setP(String receiver, int value) {
+    public void setP(@NotNull String receiver, int value) {
         p = value;
     }
 }
@@ -28,4 +30,4 @@ class Test {
         new B().getP("");
         new B().setP("", 3);
     }
-}
+}

idea/testData/refactoring/changeSignature/AddReceiverToGenericsWithOverridesAfter.1.java

@@ -1,18 +1,20 @@
+<caret>import org.jetbrains.annotations.NotNull;
+
 interface J<A> extends T<A> {
     @Override
-    <B> int foofoofoo(U<A> a, B b);
+    <B> int foofoofoo(@NotNull U<A> a, B b);
 }
 
 abstract class J1<X> implements J<U<X>> {
     @Override
-    public <C> int foofoofoo(U<U<X>> xu, C c) {
+    public <C> int foofoofoo(@NotNull U<U<X>> xu, C c) {
         throw new UnsupportedOperationException();
     }
 }
 
 abstract class J2 extends J1<String> {
     @Override
-    public <C> int foofoofoo(U<U<String>> xu, C c) {
+    public <C> int foofoofoo(@NotNull U<U<String>> xu, C c) {
         throw new UnsupportedOperationException();
     }
-}
+}