Share srcs in rust_defaults.

Test: atest -c --include-subdirs external/rust/crates
Change-Id: I281a1f386fa6c53b5af8a1b355b68119bdf53070
diff --git a/Android.bp b/Android.bp
index a1e6550..586bfb4 100644
--- a/Android.bp
+++ b/Android.bp
@@ -15,6 +15,8 @@
 rust_defaults {
     name: "unicode-width_defaults",
     crate_name: "unicode_width",
+    // has rustc warnings
+    srcs: ["src/lib.rs"],
     test_suites: ["general-tests"],
     auto_gen_config: true,
     edition: "2015",
@@ -26,13 +28,9 @@
 rust_test_host {
     name: "unicode-width_host_test_src_lib",
     defaults: ["unicode-width_defaults"],
-    // has rustc warnings
-    srcs: ["src/lib.rs"],
 }
 
 rust_test {
     name: "unicode-width_device_test_src_lib",
     defaults: ["unicode-width_defaults"],
-    // has rustc warnings
-    srcs: ["src/lib.rs"],
 }