libhidltransport: not in VNDK

b/c it is empty

Bug: 135686713
Test: build succeeds (no VNDK libraries depend on this)
Change-Id: I6b92cc22f67c9d5972d6605fe9ff492ae0bfa6b8
(cherry picked from commit 0e39b327c9260a97c2313ef02d291fd247a7f687)
diff --git a/Android.bp b/Android.bp
index 76dc28f..819732d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -111,8 +111,4 @@
 cc_library {
     name: "libhidltransport",
     vendor_available: true,
-    vndk: {
-        enabled: true,
-        support_system_process: true,
-    },
 }