Make native package manager available to platform.

Some native internal services are dependent on package manager which is
available only to specific APEXes. Also adding platform in general now.

Test: locally tested
Bug: 361877215
Change-Id: I01a015e83fbf07059936ffc2d50814d5827d609c
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index 2ef642a..628f6ea 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -829,6 +829,7 @@
     backend: {
         rust: {
             apex_available: [
+                "//apex_available:platform",
                 "com.android.virt",
             ],
             enabled: true,