Allow using once_cell from DnsResolver

Test: m
Bug: 155855709
Change-Id: Iabf9f2c67faf6e1d325db6110d12418633ec2aff
diff --git a/Android.bp b/Android.bp
index f122044..966610c 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,4 @@
-// This file is generated by cargo2android.py --run --device --dependencies.
+// This file is generated by cargo2android.py --run --device --dependencies --patch=patches/Android.bp.patch.
 
 rust_library {
     name: "libonce_cell",
@@ -11,4 +11,9 @@
         "default",
         "std",
     ],
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.resolv",
+    ],
+    min_sdk_version: "29",
 }
diff --git a/patches/Android.bp.patch b/patches/Android.bp.patch
new file mode 100644
index 0000000..c87eabf
--- /dev/null
+++ b/patches/Android.bp.patch
@@ -0,0 +1,12 @@
+--- Android.bp	2020-12-14 23:11:31.826922229 +0900
++++ Android.bp.new	2020-12-14 23:10:57.251425048 +0900
+@@ -11,4 +11,9 @@ rust_library {
+         "default",
+         "std",
+     ],
++    apex_available: [
++        "//apex_available:platform",
++        "com.android.resolv",
++    ],
++    min_sdk_version: "29",
+ }