use conlyflags in Android.bp when appropriate

Android.bp

@@ -1,5 +1,4 @@
 common_cflags = [
-    "-std=c11",
     "-O3",
     //"-flto",
     "-fPIC",
@@ -11,7 +10,6 @@ common_cflags = [
     "-Wcast-align",
     "-Wcast-qual",
     "-Wwrite-strings",
-    "-Wmissing-prototypes",
     "-DH_MALLOC_PREFIX",
     "-DZERO_ON_FREE=true",
     "-DWRITE_AFTER_FREE_CHECK=true",
@@ -32,6 +30,7 @@ cc_defaults {
     name: "hardened_malloc_defaults",
     defaults: ["linux_bionic_supported"],
     cflags: common_cflags,
+    conlyflags: ["-std=c11", "-Wmissing-prototypes"],
     stl: "none",
 }