Make libbinder_rs product_available

So it can be used in the product partition.
Required a change in cfg based on b/270718001

Test: m
Bug: 269204477
Change-Id: I5d6f334a5eb590754355876240f4a4ff5451f1c9
diff --git a/libs/binder/rust/Android.bp b/libs/binder/rust/Android.bp
index afd414a..d36ebac 100644
--- a/libs/binder/rust/Android.bp
+++ b/libs/binder/rust/Android.bp
@@ -21,6 +21,7 @@
     ],
     host_supported: true,
     vendor_available: true,
+    product_available: true,
     target: {
         darwin: {
             enabled: false,
@@ -72,6 +73,7 @@
     ],
     host_supported: true,
     vendor_available: true,
+    product_available: true,
     target: {
         darwin: {
             enabled: false,
@@ -129,6 +131,7 @@
     ],
     host_supported: true,
     vendor_available: true,
+    product_available: true,
 
     // Currently necessary for host builds
     // TODO(b/31559095): bionic on host should define this