Migrate Shadows -> Kotlin (#37563)

Summary:
Pull Request resolved: #37563

This diff migrates the Shadows project into kotlin

changelog: [internal] internal

Reviewed By: cortinico

Differential Revision: D45679204

fbshipit-source-id: eede61e725d6f4dc21d23176d2e9f72f3726f1c8

Author: mdvacca

packages/react-native/ReactAndroid/src/test/java/com/facebook/testutils/shadows/ShadowArguments.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.testutils.shadows
+
+import com.facebook.react.bridge.Arguments
+import com.facebook.react.bridge.JavaOnlyMap
+import com.facebook.react.bridge.WritableMap
+import org.robolectric.annotation.Implementation
+import org.robolectric.annotation.Implements
+
+@Implements(Arguments::class)
+class ShadowArguments {
+  companion object {
+    @JvmStatic @Implementation fun createMap(): WritableMap = JavaOnlyMap()
+  }
+}

packages/react-native/ReactAndroid/src/test/java/com/facebook/testutils/shadows/ShadowArguments.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.testutils.shadows
+
+import android.content.Context
+import com.facebook.soloader.SoLoader
+import kotlin.jvm.JvmStatic
+import org.robolectric.annotation.Implementation
+import org.robolectric.annotation.Implements
+
+@Implements(SoLoader::class)
+class ShadowSoLoader {
+  companion object {
+    @JvmStatic @Implementation fun init(context: Context?, flags: Int) {}
+
+    @JvmStatic @Implementation fun loadLibrary(shortName: String?): Boolean = true
+  }
+}