Generate apex_available from c2a instead of a patch

Test: Run c2a
Test: Build
Change-Id: If0ced6184d7b16e19a874d13e0996ca9e42a5ab3
diff --git a/Android.bp b/Android.bp
index ae913ce..d53b9c9 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,4 @@
-// This file is generated by cargo2android.py --run --device --tests --dependencies --patch=patches/Android.bp.patch.
+// This file is generated by cargo2android.py --config cargo2android.json.
 // Do not modify this file as changes will be overridden on upgrade.
 
 package {
@@ -25,11 +25,12 @@
     srcs: ["src/lib.rs"],
     edition: "2015",
     features: ["default"],
-    flags: [
-        "--cfg allow_clippy",
-        "--cfg doctests",
-        "--cfg maybe_uninit",
-        "--cfg tuple_ty",
+    cfgs: [
+        "allow_clippy",
+        "doctests",
+        "maybe_uninit",
+        "raw_ref_macros",
+        "tuple_ty",
     ],
     apex_available: [
         "//apex_available:platform",
@@ -45,11 +46,12 @@
     auto_gen_config: true,
     edition: "2015",
     features: ["default"],
-    flags: [
-        "--cfg allow_clippy",
-        "--cfg doctests",
-        "--cfg maybe_uninit",
-        "--cfg tuple_ty",
+    cfgs: [
+        "allow_clippy",
+        "doctests",
+        "maybe_uninit",
+        "raw_ref_macros",
+        "tuple_ty",
     ],
     rustlibs: [
         // ANDROID: disable for now just to avoid another dependency.