While it's not directly possible in the current version with its own keystroke, there is another very simple way to accomplish this.
First, be located in the row on which you want to insert a row above or below.
Then do the following (keys are on Mac, so translate as necessary for your OS):
- Ctrl + Option + I - invokes the Insert menu
- Then hit the R key for Row Above, or the WB key again for Row Below
I guess this way may actually be one less keystroke than how it was done before, so that's a win right there!
Alternatively, you can also just use your cursor keys (to me this is easier, even if it's more keystrokes):
- ↓ (down arrow once) for Row Above
- ↓↓ (down arrow twice) for Row Below
- Hit ⏎ (Enter).
Hope this helps!