Smaller buttons for power menu in landscape mode

When setting font & display size were set to the biggest, and we had 5
items on the power menu, the buttons would get truncated. This CL makes
buttons (and padding slightly) smaller, so that they fit nicely on the
screen.

Flag: None
Bug: 254189490
Test: Make sure there are at least 5 buttons in the power menu.
        Simultaneously, press power button and volume button up.
	The button shapes in the power menu should be whole and not
	truncated.
Change-Id: I8683d7fa074e0c0ed79c150928aa5bfa1f4aeb0c