Don't use *.rs for srcs

Rust build rules only support a single source file (which can then
reference other modules).

So avoid wildcards, and instead name the top-level file.

The only case where we had multiple sources was pvmfw/avb, which
actually seemed to be working fine.

Test: atest liblibfdt.integration_test libpvmfw_avb.integration_test
  libdiced_open_dice.integration_test libdiced_open_dice_nostd.integration_test
  libdiced_sample_inputs.integration_test libdiced_sample_inputs_nostd.integration_test
  libservice_vm_comm.test libservice_vm_comm_nostd.test
Change-Id: I64ec1829a2128eeb629b37715ab78f1b694b25e2
diff --git a/libs/dice/sample_inputs/Android.bp b/libs/dice/sample_inputs/Android.bp
index 013038c..36fe8c7 100644
--- a/libs/dice/sample_inputs/Android.bp
+++ b/libs/dice/sample_inputs/Android.bp
@@ -54,7 +54,7 @@
 rust_defaults {
     name: "libdiced_sample_inputs_test_defaults",
     crate_name: "diced_sample_inputs_test",
-    srcs: ["tests/*.rs"],
+    srcs: ["tests/api_test.rs"],
     test_suites: ["general-tests"],
     rustlibs: [
         "libanyhow",