Delete ScreenshotTestsManagerModule (facebook#53746)

Summary:
Pull Request resolved: facebook#53746

ScreenshotTestsManagerModule and ReactAppScreenshotTestActivity are not in use anymore, let's delete them

changelog: [internal] internal

Reviewed By: javache

Differential Revision: D82249453

fbshipit-source-id: 73b0f2ef2e9a5370057c07c3bee03f9c0793d61a

Author: mdvacca

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/AndroidInfoModule.kt

@@ -55,7 +55,7 @@ public class AndroidInfoModule(reactContext: ReactApplicationContext) :
       constants["ServerHost"] =
           AndroidInfoHelpers.getServerHost(reactApplicationContext.applicationContext)
     }
-    constants["isTesting"] = "true" == System.getProperty(IS_TESTING) || isRunningScreenshotTest()
+    constants["isTesting"] = "true" == System.getProperty(IS_TESTING)
     val isDisableAnimations = System.getProperty(IS_DISABLE_ANIMATIONS)
     if (isDisableAnimations != null) {
       constants["isDisableAnimations"] = "true" == isDisableAnimations
@@ -71,15 +71,6 @@ public class AndroidInfoModule(reactContext: ReactApplicationContext) :
 
   override fun invalidate() {}
 
-  private fun isRunningScreenshotTest(): Boolean {
-    return try {
-      Class.forName("com.facebook.testing.react.screenshots.ReactAppScreenshotTestActivity")
-      true
-    } catch (ignored: ClassNotFoundException) {
-      false
-    }
-  }
-
   public companion object {
     public const val NAME: String = NativePlatformConstantsAndroidSpec.NAME
     private const val IS_TESTING = "IS_TESTING"