vulkan/android: Add basic u_gralloc support

We want to move more Android-related functions into common code.
Many of which require interactions with the gralloc. Therefore,
struct u_gralloc must be kept in a common code.

vk_android_get_ugralloc() must be used for gralloc API calls.

vk_android_{init|destroy}_ugralloc() must be used in Vulkan HAL
initialization code, e.g.:
 - In XXXX_hal_open() to initialize the gralloc
 - In XXXX_hal_close() to destroy the gralloc

We do not put gralloc initialization into the generic code because we want
it to be initialized by Zygote's Vulkan preloader, which may sometimes
preload gralloc shared libraries, thus speeding up the initialization
of user applications.

Change-Id: I2af643bd132e6cdbfed043c8c18836501764952f
Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
Tested-by: tarsin <yuanqingxiang233@163.com>
Acked-by: David Heidelberg <david.heidelberg@collabora.com>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25360>

src/vulkan/runtime/vk_android.c

@@ -40,6 +40,28 @@
 
 #include <unistd.h>
 
+static struct u_gralloc *u_gralloc;
+
+struct u_gralloc *
+vk_android_get_ugralloc(void)
+{
+   return u_gralloc;
+}
+
+struct u_gralloc *
+vk_android_init_ugralloc(void)
+{
+   u_gralloc = u_gralloc_create(U_GRALLOC_TYPE_AUTO);
+
+   return u_gralloc;
+}
+
+void
+vk_android_destroy_ugralloc(void)
+{
+   u_gralloc_destroy(&u_gralloc);
+}
+
 #if ANDROID_API_LEVEL >= 26
 #include <vndk/hardware_buffer.h>