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: I63923fcb6c11a2c331606f5b0b71e9f4c4cd7322

Android.bp

@@ -31,6 +31,9 @@ cc_library_static {
 cc_library_shared {
     name: "libpiex",
     vendor_available: true,
+    vndk: {
+        enabled: true,
+    },
     srcs: [
         "src/tiff_parser.cc",
         "src/piex.cc",