Android Question Nexus 4 is showing a resolution of 1196 X 768 on the UI Cloud but Google reports it as 1280 X 768

If you are not using the designer scripts, that's a possibility, another possibility is that you are working with a "fixed" screen size, but, without knowing how you are creating your layouts is going to be a guessing game.

the screen height 1280 but the activity height maybe 1196 because of the software buttons

The UI Cloud values do not include the system bars (change the full screen / include title properties to see it). However you shouldn't try to match any single device. Instead use anchors and the designer script feature to create a flexible layout.