binder_rs: Implement ParcelableHolder

Implement the Rust version of ParcelableHolder.

Bug: 169035750
Test: m
Change-Id: Ic21ee54a722ed54c6cf33d4489d93320b1374573
diff --git a/libs/binder/rust/Android.bp b/libs/binder/rust/Android.bp
index d9d7caf..ecb044e 100644
--- a/libs/binder/rust/Android.bp
+++ b/libs/binder/rust/Android.bp
@@ -17,6 +17,7 @@
     rustlibs: [
         "liblibc",
         "libbinder_ndk_sys",
+        "libdowncast_rs",
     ],
     host_supported: true,
     target: {
@@ -133,6 +134,7 @@
     rustlibs: [
         "liblibc",
         "libbinder_ndk_sys",
+        "libdowncast_rs",
     ],
 }