Use the newly introduced whole_program_vtables property

... instead of manually adding -fwhole-program-vtables cflag.

Test: build
Bug: 169004486
Change-Id: Ie04b0ef3d5621b8304b6c04f92a00411cb0ea3ec
diff --git a/services/gpuservice/Android.bp b/services/gpuservice/Android.bp
index 6eed24a..4da6db3 100644
--- a/services/gpuservice/Android.bp
+++ b/services/gpuservice/Android.bp
@@ -42,11 +42,11 @@
     defaults: ["libgpuservice_defaults"],
     cflags: [
         "-fvisibility=hidden",
-        "-fwhole-program-vtables", // requires ThinLTO
     ],
     lto: {
         thin: true,
     },
+    whole_program_vtables: true, // Requires ThinLTO
 }
 
 filegroup {