Enable rust backend for android.hardware.bluetooth(.audio)

Bug: 312265159
Test: TreeHugger
Change-Id: Id1098a8deb6e83f3b33dec2a982f68450cb0f510
diff --git a/bluetooth/audio/aidl/Android.bp b/bluetooth/audio/aidl/Android.bp
index ae55fa9..dbff368 100644
--- a/bluetooth/audio/aidl/Android.bp
+++ b/bluetooth/audio/aidl/Android.bp
@@ -38,6 +38,9 @@
         cpp: {
             enabled: false,
         },
+        rust: {
+            enabled: true,
+        },
         java: {
             sdk_version: "module_current",
             enabled: false,
@@ -86,7 +89,6 @@
 
     ],
     frozen: false,
-
 }
 
 // Note: This should always be one version ahead of the last frozen version