Expose DevSupportHttpClient as public API (#55778)

Summary:
Pull Request resolved: #55778

Revert the `DevSupportRequestHeaders` extraction from D94354168 and instead
make `DevSupportHttpClient` itself `public`. This gives external consumers
(e.g. Expo Dev Launcher) direct access to the shared OkHttpClient instances
and the `addRequestHeader`/`removeRequestHeader` methods without needing a
separate intermediary singleton.

Changes:
- Remove `DevSupportRequestHeaders` class and its `request_headers` Buck target
- Change `DevSupportHttpClient` from `internal` to `public`
- Restore `addRequestHeader`/`removeRequestHeader` methods in `DevSupportHttpClient`
- Revert `interfaces` Buck target to include all `interfaces/*.kt` files
- Revert inspector Buck target to remove the `request_headers` dependency

This looks breaking from the API prespective but `DevSupportRequestHeaders` was never shipped, so it's just an addittive change.

Changelog: [Android][Added] - Make DevSupportHttpClient public for custom dev-support HTTP header registration

Reviewed By: cipolleschi

Differential Revision: D94515394

fbshipit-source-id: 709eb0e039f9b0a21d67b042dc9df0fc287720de

Author: cortinico

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -2101,6 +2101,14 @@ public final class com/facebook/react/devsupport/StackTraceHelper$StackFrameImpl
 	public fun toJSON ()Lorg/json/JSONObject;
 }
 
+public final class com/facebook/react/devsupport/inspector/DevSupportHttpClient {
+	public static final field INSTANCE Lcom/facebook/react/devsupport/inspector/DevSupportHttpClient;
+	public static final fun addRequestHeader (Ljava/lang/String;Ljava/lang/String;)V
+	public final fun getHttpClient ()Lokhttp3/OkHttpClient;
+	public final fun getWebsocketClient ()Lokhttp3/OkHttpClient;
+	public static final fun removeRequestHeader (Ljava/lang/String;)V
+}
+
 public abstract interface class com/facebook/react/devsupport/interfaces/BundleLoadCallback {
 	public fun onError (Ljava/lang/Exception;)V
 	public abstract fun onSuccess ()V
@@ -2184,13 +2192,6 @@ public abstract interface class com/facebook/react/devsupport/interfaces/DevSupp
 	public abstract fun onResume ()V
 }
 
-public final class com/facebook/react/devsupport/interfaces/DevSupportRequestHeaders {
-	public static final field INSTANCE Lcom/facebook/react/devsupport/interfaces/DevSupportRequestHeaders;
-	public static final fun addRequestHeader (Ljava/lang/String;Ljava/lang/String;)V
-	public static final fun allHeaders ()Ljava/util/Map;
-	public static final fun removeRequestHeader (Ljava/lang/String;)V
-}
-
 public abstract interface class com/facebook/react/devsupport/interfaces/ErrorCustomizer {
 	public abstract fun customizeErrorInfo (Landroid/util/Pair;)Landroid/util/Pair;
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/inspector/DevSupportHttpClient.kt

@@ -9,33 +9,29 @@
 
 package com.facebook.react.devsupport.inspector
 
-import com.facebook.react.devsupport.interfaces.DevSupportRequestHeaders
+import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.TimeUnit
 import okhttp3.Interceptor
 import okhttp3.OkHttpClient
 
 /**
  * Shared [OkHttpClient] instances for devsupport networking. Uses a single connection pool and
- * dispatcher across all dev support HTTP and WebSocket usage. Injects custom request headers
- * registered via [DevSupportRequestHeaders] into every outgoing request.
+ * dispatcher across all dev support HTTP and WebSocket usage. Supports injecting custom request
+ * headers that are applied to every outgoing request via an OkHttp interceptor.
  */
-internal object DevSupportHttpClient {
+public object DevSupportHttpClient {
+  private val customHeaders = ConcurrentHashMap<String, String>()
+
   private val headerInterceptor = Interceptor { chain ->
-    val originalRequest = chain.request()
-    val headers = DevSupportRequestHeaders.allHeaders()
-    if (headers.isEmpty()) {
-      chain.proceed(originalRequest)
-    } else {
-      val builder = originalRequest.newBuilder()
-      for ((name, value) in headers) {
-        builder.header(name, value)
-      }
-      chain.proceed(builder.build())
+    val builder = chain.request().newBuilder()
+    for ((name, value) in customHeaders) {
+      builder.header(name, value)
     }
+    chain.proceed(builder.build())
   }
 
   /** Client for HTTP requests: connect=5s, write=disabled, read=disabled. */
-  val httpClient: OkHttpClient =
+  public val httpClient: OkHttpClient =
       OkHttpClient.Builder()
           .addInterceptor(headerInterceptor)
           .connectTimeout(5, TimeUnit.SECONDS)
@@ -44,10 +40,22 @@ internal object DevSupportHttpClient {
           .build()
 
   /** Client for WebSocket connections: connect=10s, write=10s, read=disabled. */
-  val websocketClient: OkHttpClient =
+  public val websocketClient: OkHttpClient =
       httpClient
           .newBuilder()
           .connectTimeout(10, TimeUnit.SECONDS)
           .writeTimeout(10, TimeUnit.SECONDS)
           .build()
+
+  /** Add a custom header to be included in all requests made through both clients. */
+  @JvmStatic
+  public fun addRequestHeader(name: String, value: String) {
+    customHeaders[name] = value
+  }
+
+  /** Remove a previously added custom header. */
+  @JvmStatic
+  public fun removeRequestHeader(name: String) {
+    customHeaders.remove(name)
+  }
 }