[vulkan] Fix blend constants encoding error

bug: 111137294

Wow :)

Change-Id: I724b0a641b22495897b72db19b2e2771a96689fc
diff --git a/system/vulkan_enc/VkEncoder.cpp b/system/vulkan_enc/VkEncoder.cpp
index b97f120..42487ea 100644
--- a/system/vulkan_enc/VkEncoder.cpp
+++ b/system/vulkan_enc/VkEncoder.cpp
@@ -7137,7 +7137,7 @@
 
 void VkEncoder::vkCmdSetBlendConstants(
     VkCommandBuffer commandBuffer,
-    const float blendConstants)
+    const float blendConstants[4])
 {
     AEMU_SCOPED_TRACE("vkCmdSetBlendConstants encode");
     mImpl->log("start vkCmdSetBlendConstants");