android: allow registering custom packager command handlers

Summary:
@public
Apps may need to listen for custom commands via the packager connection. This allows registering such listeners.

Reviewed By: raluca-elena

Differential Revision: D8654477

fbshipit-source-id: 5f17298a88fec31b8939236fef48ee46c0ba2ee8

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManagerBuilder.java

@@ -21,8 +21,10 @@ import com.facebook.react.devsupport.RedBoxHandler;
 import com.facebook.react.devsupport.interfaces.DevBundleDownloadListener;
 import com.facebook.react.devsupport.interfaces.DevSupportManager;
 import com.facebook.react.modules.core.DefaultHardwareBackBtnHandler;
+import com.facebook.react.packagerconnection.RequestHandler;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import javax.annotation.Nullable;
 
 /**
@@ -50,6 +52,7 @@ public class ReactInstanceManagerBuilder {
   private int mMinNumShakes = 1;
   private int mMinTimeLeftInFrameForNonBatchedOperationMs = -1;
   private @Nullable JSIModulePackage mJSIModulesPackage;
+  private @Nullable Map<String, RequestHandler> mCustomPackagerCommandHandlers;
 
   /* package protected */ ReactInstanceManagerBuilder() {
   }
@@ -216,6 +219,12 @@ public class ReactInstanceManagerBuilder {
     return this;
   }
 
+  public ReactInstanceManagerBuilder setCustomPackagerCommandHandlers(
+      Map<String, RequestHandler> customPackagerCommandHandlers) {
+    mCustomPackagerCommandHandlers = customPackagerCommandHandlers;
+    return this;
+  }
+
   /**
    * Instantiates a new {@link ReactInstanceManager}.
    * Before calling {@code build}, the following must be called:
@@ -266,6 +275,7 @@ public class ReactInstanceManagerBuilder {
         mDevBundleDownloadListener,
         mMinNumShakes,
         mMinTimeLeftInFrameForNonBatchedOperationMs,
-        mJSIModulesPackage);
+        mJSIModulesPackage,
+        mCustomPackagerCommandHandlers);
   }
 }