Fix Nullsafe FIXMEs for JSDebuggerWebSocketClient.java and mark nullsafe (#50058)

Summary:
Pull Request resolved: #50058

Gone trough all the FIXMEs added in the previous diff by the nullsafe tool, marked the class as nullsafe and ensured no remaining violations.

Changelog: [Android][Fixed] Made JSDebuggerWebsocketClient.java nullsafe

Reviewed By: mdvacca

Differential Revision: D71126385

fbshipit-source-id: 8707e8c6b8092c0c301dc81a363758b60f38086a

Author: GijsWeterings

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/JSDebuggerWebSocketClient.java

@@ -13,6 +13,7 @@
 import androidx.annotation.Nullable;
 import com.facebook.common.logging.FLog;
 import com.facebook.infer.annotation.Assertions;
+import com.facebook.infer.annotation.Nullsafe;
 import com.facebook.react.common.JavascriptException;
 import com.facebook.react.common.annotations.VisibleForTesting;
 import java.io.IOException;
@@ -29,6 +30,7 @@
 import okhttp3.WebSocketListener;
 
 /** A wrapper around WebSocketClient that recognizes RN debugging message format. */
+@Nullsafe(Nullsafe.Mode.LOCAL)
 class JSDebuggerWebSocketClient extends WebSocketListener {
 
   private static final String TAG = "JSDebuggerWebSocketClient";
@@ -210,8 +212,7 @@ public void onMessage(@Nullable WebSocket webSocket, String text) {
   }
 
   @Override
-  // NULLSAFE_FIXME[Inconsistent Subclass Parameter Annotation]
-  public void onFailure(WebSocket webSocket, Throwable t, Response response) {
+  public void onFailure(@Nullable WebSocket webSocket, Throwable t, @Nullable Response response) {
     abort("Websocket exception", t);
   }
 

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/devsupport/JSDebuggerWebSocketClientTest.kt

@@ -41,7 +41,7 @@ class JSDebuggerWebSocketClientTest {
     val client = spy(JSDebuggerWebSocketClient())
     val injectedObjects = mapOf("key1" to "value1", "key2" to "value2")
     client.loadBundle(
-        "http://localhost:8080/index.js", injectedObjects as HashMap<String, String>?, cb)
+        "http://localhost:8080/index.js", injectedObjects as HashMap<String, String>, cb)
     verify(client)
         .sendMessage(
             0,