Mark the modules as VNDK-SP in Android.bp

As a VNDK-SP module, Android.bp must have 'vndk' tag as well as
'vendor_available: true'.

The 'vndk' tag for VNDK-SP formated as follows:
vndk: {
    enabled: true,
    support_system_process: true,
},

VNDK-SP modules will be installed both in system/lib(64) as normal
and in system/lib(64)/vndk-sp as a vendor variant.

Bug: 63866913
Test: build and boot with BOARD_VNDK_VERSION=current
Change-Id: I51fe0859f63ad58b7b91909e7d7d4206443228cd
diff --git a/libutils/Android.bp b/libutils/Android.bp
index 9e7cc13..a779a8c 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -46,6 +46,10 @@
 cc_library {
     name: "libutils",
     vendor_available: true,
+    vndk: {
+        enabled: true,
+        support_system_process: true,
+    },
     host_supported: true,
 
     srcs: [