Generate apex_available from c2a instead of a patch

Test: Run c2a
Test: Build
Change-Id: Id8ea72ae45a08a3fb831d24c3202503ce3979ae8
diff --git a/Android.bp b/Android.bp
index 8eaf57e..774be52 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,5 @@
-// This file is generated by cargo2android.py --run --dependencies --device --features= --tests.
+// This file is generated by cargo2android.py --config cargo2android.json.
+// Do not modify this file as changes will be overridden on upgrade.
 
 package {
     default_applicable_licenses: ["external_rust_crates_env_logger_license"],
@@ -67,9 +68,7 @@
     test_suites: ["general-tests"],
     auto_gen_config: true,
     edition: "2018",
-    flags: [
-        "--cfg test",
-    ],
+    cfgs: ["test"],
     rustlibs: [
         "libenv_logger",
         "liblog_rust",