Remove moduleSpecName

Summary:
All our codegen JavaScript now simply uses libraryName instead of moduleSpecName. In our buck infra, we assign native_module_spec_name to libraryName.

Changelog: [Internal]

Reviewed By: fkgozali

Differential Revision: D25842696

fbshipit-source-id: efd3af402585f9ad4ff3b593179147eea91cc331

packages/react-native-codegen/src/generators/modules/GenerateModuleJavaSpec.js

@@ -367,7 +367,6 @@ module.exports = {
   generate(
     libraryName: string,
     schema: SchemaType,
-    moduleSpecName: string,
     packageName?: string,
   ): FilesOutput {
     const files = new Map();