I tried this after 2.7 update and its working!!!!
This is new glitch in injustice and also very easy.
Steps to follow:
1 go to store.
2 go to sell tab.and then go to upgrades.
3 now tap fastly the sequence : characters tab=character card=upgrades tab.
Hat tip to bdckr gaming for demonstrating this glitch first,here is the link for their video:
like, subscribe for more such videos!!