Mark the module as VNDK or VNDK-SP in Android.bp

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

For a VNDK module, the 'vndk' tag has 'enabled: true'.
It will be installed system/lib(64)/vndk as a vendor variant.

For a VNDK-SP module, the 'vndk' tag has
'support_system_process: true' as well as 'enabled: true'.
It will be installed system/lib(64)/vndk-sp as a vendor variant.

Bug: 63866913
Test: build and boot with BOARD_VNDK_VERSION=current
Change-Id: I7d6c67c2bad5fe77c02fb30fa52efb6a932eecd5
diff --git a/Android.bp b/Android.bp
index c351493..b62d197 100644
--- a/Android.bp
+++ b/Android.bp
@@ -28,6 +28,10 @@
     include_dirs: ["frameworks/native/include"],
 
     vendor_available: true,
+    vndk: {
+        enabled: true,
+        support_system_process: true,
+    },
     clang: true,
     sanitize: {
         misc_undefined: ["integer"],