Mark libui as vendor_available

libui is used by libgui and libstagefright_foundation which are both in
VNDK. So libui should also be in VNDK.

Bug: 37731063
Test: sailfish builds and boots
Test: 'BOARD_VNDK_VERSION=current m libui' successful
Change-Id: Ia8172a42325e5b5181741dda70048dc68e778b76
diff --git a/libs/ui/Android.bp b/libs/ui/Android.bp
index c2e93d8..fb553e2 100644
--- a/libs/ui/Android.bp
+++ b/libs/ui/Android.bp
@@ -14,6 +14,7 @@
 
 cc_library_shared {
     name: "libui",
+    vendor_available: true,
 
     clang: true,
     cppflags: [
@@ -60,6 +61,10 @@
         "UiConfig.cpp",
     ],
 
+    include_dirs: [
+        "frameworks/native/include",
+    ],
+
     shared_libs: [
         "android.hardware.graphics.allocator@2.0",
         "android.hardware.graphics.mapper@2.0",
@@ -73,7 +78,6 @@
         "libsync",
         "libutils",
         "liblog",
-        "libgraphicsenv",
     ],
 
     static_libs: [