C++17 is now the default.

Test: builds
Change-Id: Ib96ce1db95dfef6d2b5a269ee47dbd0a89650bc4
diff --git a/keystore/Android.bp b/keystore/Android.bp
index 366f591..c1d81b3 100644
--- a/keystore/Android.bp
+++ b/keystore/Android.bp
@@ -13,7 +13,6 @@
     },
 
     clang: true,
-    cpp_std: "c++17",
 }
 
 cc_binary {