Use the default C version.

This project no longer requires "experimental" to build.

Bug: http://b/232413369
Test: treehugger
Change-Id: Ia3dcc0fb57f3c41cd564d6329f3facd941522d26
diff --git a/Android.bp b/Android.bp
index d1c2647..5cfb626 100644
--- a/Android.bp
+++ b/Android.bp
@@ -66,7 +66,6 @@
         "-include prebuilt-intermediates/config.h",
         "-Wno-unused-parameter",
     ],
-    c_std: "experimental",
     local_include_dirs: [
         "prebuilt-intermediates",
         "src",