vulkan: Adjust ANDROID_native_buffer to match new shared image naming

Rename the SWAPCHAIN_IMAGE_USAGE_FRONT_BUFFER_BIT to
SWAPCHAIN_IMAGE_USAGE_SHARED_BIT, to match Khronos renames.

Change-Id: I380512a66221c8cfcc650cd7e8259a185d61604d
Test: build
diff --git a/vulkan/api/vulkan.api b/vulkan/api/vulkan.api
index 3b79d5a..cdc69b0 100644
--- a/vulkan/api/vulkan.api
+++ b/vulkan/api/vulkan.api
@@ -1568,7 +1568,7 @@
 type VkFlags VkSwapchainImageUsageFlagsANDROID
 @extension("VK_ANDROID_native_buffer")
 bitfield VkSwapchainImageUsageFlagBitsANDROID {
-    VK_SWAPCHAIN_IMAGE_USAGE_FLAGS_FRONT_BUFFER_BIT_ANDROID = 0x00000001,
+    VK_SWAPCHAIN_IMAGE_USAGE_FLAGS_SHARED_BIT_ANDROID = 0x00000001,
 }
 
 @extension("VK_NV_external_memory_capabilities")