lights: Add Rust backend to the lights AIDL

This enables us to write a lights service in Rust.

Bug: 286106270
Tested: Verified with a WIP replacement for the Lights example service.
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:a37bed645683cec20b67b8303aa8e3f6ac08f32a)
Change-Id: I6f9838ea711fb194ac9b9f7b3c29eeb87491beb8
diff --git a/light/aidl/Android.bp b/light/aidl/Android.bp
index c11934f..c9fba95 100644
--- a/light/aidl/Android.bp
+++ b/light/aidl/Android.bp
@@ -18,6 +18,9 @@
         java: {
             sdk_version: "module_current",
         },
+        rust: {
+            enabled: true,
+        },
     },
     versions_with_info: [
         {