Revert "In app_generator, fix hardcoded bundle call to derive the bundle executable name from Thor::Util.ruby_command."

This reverts commit 6f4c45199b.

This breaks the tests. Please investigate.

railties/lib/generators/rails/app/app_generator.rb

@@ -178,8 +178,7 @@ module Rails::Generators
     end
 
     def bundle_if_dev_or_edge
-      bundle_command = Thor::Util.ruby_command.sub(%r[ruby(?=[^/]*$)], 'bundle')
-      run "#{bundle_command} install" if dev_or_edge?
+      run "bundle install" if dev_or_edge?
     end
 
     protected