Vulkan: Prefer MAILBOX over IMMEDIATE present mode When swap interval is 0, either MAILBOX or IMMEDIATE present modes could be chosen. MAILBOX produces no tearing, so this change prefers that. Bug: angleproject:3163 Change-Id: I80b3c5820358b398ddf0eeba546d1ec10bae3d84 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3628018 Reviewed-by: Ian Elliott <ianelliott@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>