fix Vulkan destroy blocking main thread causing UI lag

Set isRendererReady = false in releaseRenderSurface() so that
destroy() takes the fast path and signals the main thread
immediately instead of waiting for full synchronous cleanup
on the render thread. This is consistent with GLMapboxRenderThread
which sets isRendererReady = false in releaseEglSurface().

GitOrigin-RevId: ea68c9d827e73359ef1684717fd9ae7c1975d7e5

Author: pengdev

maps-sdk/src/main/java/com/mapbox/maps/renderer/VulkanMapboxRenderThread.kt

@@ -90,6 +90,7 @@ internal class VulkanMapboxRenderThread(mapboxRenderer: MapboxRenderer, mapName:
 
   override fun releaseRenderSurface() {
     nativeVulkanManager?.releaseSurface()
+    isRendererReady = false
   }
 
   override fun clearRendererStateListeners() {