Tip: We can write git commands in "Terminal" of Android Studio
git revert --no-commit HEAD~2..
// then to commit with message
git commit -m 'the commit message' // or use commit from GUI
git rev-list HEAD --count
//add desired file using GUI or add command then
git commit --amend --no-edit //to commit with previous commit message
git commit --amend -m "Message" //to commit with new commit message
http://stackoverflow.com/a/9171451
git clean -f -d