egl: Add logic to select preferred display ChromeOS Flex devices can have multiple GPUs, and some of these will have persistent issues. Chrome worked around this by preferring well-supported GPU vendors over others. Add this logic and refactor inintialization to minimize code duplication. Bug: b/298460913 Change-Id: Ibac394988b7385fca35b98f0e3834b056484ba82 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5320107 Commit-Queue: Allen Ballway <ballway@google.com> Reviewed-by: Geoff Lang <geofflang@chromium.org>