Update Android.bp by running cargo_embargo am: f273245e15

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/futures-macro/+/3095426

Change-Id: I17e8ac7975346dd2a95c2cf12bc7fbcb50ef74f2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

Android.bp

diff --git a/Android.bp b/Android.bp
index 1d34b10..7b4326a 100644
--- a/Android.bp
+++ b/Android.bp
@@ -44,7 +44,7 @@
     crate_name: "futures_macro",
     cargo_env_compat: true,
     cargo_pkg_version: "0.3.30",
-    srcs: ["src/lib.rs"],
+    crate_root: "src/lib.rs",
     edition: "2018",
     rustlibs: [
         "libproc_macro2",