Add 320x480 animation (generated with build/tools/resizebootani)

resized from 720x1280.zip, so individual images are 270x480, but desc indicates 320x480

Change-Id: I87aaa2d5d7c28e067d92b977b9121f5871520611
Coconut: give my watch's screen a run for its money.

Change-Id: I42b6d7f141153df8c27a5c452748347eb1b6877c