libvulkan: Reset window before creating swapchain

When using one window for two consecutive swapchains, some of the
settings from the first swapchain were affecting how many buffers we
thought we needed for the second, eventually leading us to attempt to
dequeue more buffers than we actually could.

Bug: 28075694
Change-Id: I7d2cabc2365986dfcfe8a03d16bb71ca1616f144