3bb1764557
In https://github.com/flutter/engine/pull/41059 the Android context and surface were changed to share one impeller::ContextVK across all instances of AndroidSurfaceVulkanImpeller. However, the ContextVK holds a reference to the current swapchain. If an app uses multiple AndroidSurfaceVulkanImpeller instances (e.g. for platform views), then one surface may overwrite the ContextVK's swapchain while another surface is trying to render. This patch allows each surface to get its own impeller::Context instance holding a swapchain tied to that surface. The per-surface contexts will delegate most operations to the shared parent ContextVK.