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/pvmfw/avb/Android.bp b/pvmfw/avb/Android.bp
index 6101a0c..558152d 100644
--- a/pvmfw/avb/Android.bp
+++ b/pvmfw/avb/Android.bp
@@ -25,7 +25,7 @@
     name: "libpvmfw_avb.integration_test",
     crate_name: "pvmfw_avb_test",
     defaults: ["avf_build_flags_rust"],
-    srcs: ["tests/*.rs"],
+    srcs: ["tests/api_test.rs"],
     test_suites: ["general-tests"],
     data: [
         ":avb_testkey_rsa2048_pub_bin",