[clang] Fix missing header after libc++ update

Upstream libc++ has changed a transitive header dependency. The upstream
PR is here: https://github.com/llvm/llvm-project/pull/82880 and no
longer transitively brought <cstdlib>.

Fix: 328085502
Change-Id: I556e43e337079ef56ea037113ec0d078ebe85478
diff --git a/system/vulkan_enc/goldfish_vk_counting_guest.cpp b/system/vulkan_enc/goldfish_vk_counting_guest.cpp
index 2a023a7..9fbd1d6 100644
--- a/system/vulkan_enc/goldfish_vk_counting_guest.cpp
+++ b/system/vulkan_enc/goldfish_vk_counting_guest.cpp
@@ -31,6 +31,7 @@
 
 #include "goldfish_vk_counting_guest.h"
 
+#include <cstdlib>
 #include <cstring>
 
 #include "goldfish_vk_extension_structs_guest.h"