Vulkan: Fix debug marker handling Used passed length in InsertEventMarker and PushGroupMarker commands because markers do not have to be null-terminated. Bug: angleproject:408709155 Change-Id: I6221223dabc1b01dbc175bfb7f5aeb41b9e67c6f Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6552401 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com>