Disable Rust backend for FMQ type

There are no Rust libraries for FMQ and the aidl compiler does not
generate usable code.

Test: na
Bug: none
Change-Id: Ic49f8d38f9313da3494bf1a72c4382c12bbdd726

common/fmq/aidl/Android.bp

@@ -24,9 +24,14 @@ aidl_interface {
     stability: "vintf",
     backend: {
         java: {
+            // There is no Java FMQ library, but we support the AIDL type
+            // to allow subsets of interfaces that include it to be used in Java
+            enabled: true,
             sdk_version: "module_current",
         },
         cpp: {
+            // FMQ will not be supported in the cpp backend because the parcelables
+            // are not stable enough for use in shared memory
             enabled: false,
         },
         ndk: {
@@ -38,8 +43,9 @@ aidl_interface {
             min_sdk_version: "29",
         },
         rust: {
-            enabled: true,
-        }
+            // FMQ is not supported in the rust backend
+            enabled: false,
+        },
     },
     frozen: true,
     versions: ["1"],