vulkan: allow drivers to see image acquire/release

Change-Id: I8143aeebd1f65142486cc55662c685d081ba41eb
(cherry picked from commit 58b4df743ecad9f1a0fc7cb7c0f5340dd8365308)
diff --git a/vulkan/libvulkan/loader.h b/vulkan/libvulkan/loader.h
index 74694a8..6999e1e 100644
--- a/vulkan/libvulkan/loader.h
+++ b/vulkan/libvulkan/loader.h
@@ -203,6 +203,8 @@
 
     // Implemented only by drivers, not by layers or the loader
     PFN_vkGetSwapchainGrallocUsageANDROID GetSwapchainGrallocUsageANDROID;
+    PFN_vkAcquireImageANDROID AcquireImageANDROID;
+    PFN_vkQueueSignalReleaseImageANDROID QueueSignalReleaseImageANDROID;
     PFN_vkImportNativeFenceANDROID ImportNativeFenceANDROID;
     PFN_vkQueueSignalNativeFenceANDROID QueueSignalNativeFenceANDROID;
 };