Annotate NullSafe(LOCAL) for classes in java/com/facebook/react/modules (#49769)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49769

Nullsafety scripts and analysis determine it's safe to annotate these classes as NullSafe(LOCAL)

changelog: [internal] internal

Reviewed By: rshest

Differential Revision: D70464130

fbshipit-source-id: b6819efc06e0a25a5de32842536175177c42c7b6

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/network/OkHttpCompat.java

@@ -7,6 +7,8 @@
 
 package com.facebook.react.modules.network;
 
+import androidx.annotation.Nullable;
+import com.facebook.infer.annotation.Nullsafe;
 import java.util.Collections;
 import java.util.Map;
 import okhttp3.Headers;
@@ -20,12 +22,13 @@ import okhttp3.OkHttpClient;
  * different RN platform environments, and then consider getting rid of this compat layer
  * altogether.
  */
+@Nullsafe(Nullsafe.Mode.LOCAL)
 public class OkHttpCompat {
   public static CookieJarContainer getCookieJarContainer(OkHttpClient client) {
     return (CookieJarContainer) client.cookieJar();
   }
 
-  public static Headers getHeadersFromMap(Map<String, String> headers) {
+  public static Headers getHeadersFromMap(@Nullable Map<String, String> headers) {
     if (headers == null) {
       return Headers.of(Collections.emptyMap());
     } else {