Google3 Android no longer has undefok.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1826793002

Review URL: https://codereview.chromium.org/1826793002
diff --git a/tools/flags/SkCommandLineFlags.cpp b/tools/flags/SkCommandLineFlags.cpp
index 3dd746c..9205f47 100644
--- a/tools/flags/SkCommandLineFlags.cpp
+++ b/tools/flags/SkCommandLineFlags.cpp
@@ -11,8 +11,8 @@
 
 #include <stdlib.h>
 
-#if defined(GOOGLE3) && (defined(SK_BUILD_FOR_ANDROID) || defined(SK_BUILD_FOR_IOS))
-    // I don't know why, but this is defined by //base only for non-Linux.
+#if defined(GOOGLE3) && defined(SK_BUILD_FOR_IOS)
+    // This is defined by //base only for iOS (I don't know why).
     DECLARE_bool(undefok)
 #else
     DEFINE_bool(undefok, false, "Silently ignore unknown flags instead of crashing.");