Merge "Add flags for switching RE to Vulkan and Graphite" into main

  bug: "286084594"

  is_fixed_read_only: true

}

flag {

  name: "vulkan_renderengine"

  namespace: "core_graphics"

  description: "Use Vulkan backend in RenderEngine prior to switching to Graphite."

  bug: "293371537"

  is_fixed_read_only: true

}

flag {

  name: "graphite_renderengine"

  namespace: "core_graphics"

  description: "Use Skia's Graphite Vulkan backend in RenderEngine."

  bug: "293371537"

  is_fixed_read_only: true

}