composer3: add rust backend 

Change-Id: I2d3d91fd714130252d63b697958f128c9bd06dc5
Test: presubmit
Bug: 293256928
diff --git a/graphics/composer/aidl/Android.bp b/graphics/composer/aidl/Android.bp
index 88abb73..c105ad4 100644
--- a/graphics/composer/aidl/Android.bp
+++ b/graphics/composer/aidl/Android.bp
@@ -54,6 +54,9 @@
                 enabled: true,
             },
         },
+        rust: {
+            enabled: true,
+        },
     },
     versions_with_info: [
         {