Generate apex_available from c2a instead of a patch

Test: Run c2a
Test: Build
Change-Id: Id081a50c6da633b4a3290184440c02a53af108c6
diff --git a/Android.bp b/Android.bp
index cd38e9a..c61b680 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,4 @@
-// This file is generated by cargo2android.py --run --device --features channel,default,io,memchr,sink --dependencies --tests --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 {
@@ -152,15 +152,15 @@
 //   crossbeam-utils-0.7.2 "default,lazy_static,std"
 //   fnv-1.0.7 "default,std"
 //   futures-0.1.31 "default,use_std,with-deprecated"
-//   futures-channel-0.3.13 "alloc,std"
-//   futures-core-0.3.13 "alloc,std"
-//   futures-io-0.3.13 "std"
+//   futures-channel-0.3.14 "alloc,std"
+//   futures-core-0.3.14 "alloc,std"
+//   futures-io-0.3.14 "std"
 //   futures-macro-0.3.13
-//   futures-sink-0.3.13
-//   futures-task-0.3.13 "alloc,std"
+//   futures-sink-0.3.14
+//   futures-task-0.3.14 "alloc,std"
 //   iovec-0.1.4
 //   lazy_static-1.4.0
-//   libc-0.2.92 "default,std"
+//   libc-0.2.94 "default,std"
 //   lock_api-0.3.4
 //   log-0.4.14
 //   maybe-uninit-2.0.0
@@ -182,9 +182,9 @@
 //   scopeguard-1.1.0
 //   semver-0.9.0 "default"
 //   semver-parser-0.7.0
-//   slab-0.4.2
+//   slab-0.4.3 "default,std"
 //   smallvec-0.6.14 "default,std"
-//   syn-1.0.68 "clone-impls,default,derive,full,parsing,printing,proc-macro,quote"
+//   syn-1.0.70 "clone-impls,default,derive,full,parsing,printing,proc-macro,quote"
 //   tokio-0.1.22 "bytes,codec,default,fs,io,mio,num_cpus,reactor,rt-full,sync,tcp,timer,tokio-codec,tokio-current-thread,tokio-executor,tokio-fs,tokio-io,tokio-reactor,tokio-sync,tokio-tcp,tokio-threadpool,tokio-timer,tokio-udp,tokio-uds,udp,uds"
 //   tokio-codec-0.1.2
 //   tokio-current-thread-0.1.7