[Target] Return to putting the module name in the module map path

This ensures Xcode won’t try to automatically pull in modulemap files that it encounters, causing “duplicate definition of module” errors

lib/cocoapods/target.rb

@@ -157,7 +157,7 @@ module Pod
     #         defines the module structure for the compiler.
     #
     def module_map_path
-      support_files_dir + 'module.modulemap'
+      support_files_dir + "#{product_module_name}.modulemap"
     end
 
     # @return [Pathname] the absolute path of the bridge support file.