Revert "[third_party][android] Add -Wno-vla-cxx-extension"

This reverts commit 63dee67277ed5d67441b5102d239a8c6e5aba5f8.

Reason for revert: Did not resolve Clang errors - the cflags need to be specified elsewhere.

Original change's description:
> [third_party][android] Add -Wno-vla-cxx-extension
>
> Clang now warns for uses of variable length arrays (VLA) in C++.
> Suppress this warning for libbase/logging_splitters.h use of VLA.
>
> Bug: 135694
> Change-Id: Ic39be124458e4d516c595465e5d5ee384ccf6f3b
> Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/android.googlesource.com/platform/system/libbase/+/942518
> Reviewed-by: Petr Hosek <phosek@google.com>

Bug: 135694
Change-Id: Ie8e8bd268947e44ea5d25f5e55218696dc773e81
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/android.googlesource.com/platform/system/libbase/+/943518
Reviewed-by: RubberStamper 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/BUILD.gn b/BUILD.gn
index c5efab3..e28e9cb 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -4,12 +4,6 @@
 
 config("headers") {
   include_dirs = [ "include" ]
-
-  cflags = [
-    # TODO(fxbug.dev/135166): Remove -Wno-unknown-warning-option after the next Clang roll.
-    "-Wno-unknown-warning-option",
-    "-Wno-vla-cxx-extension",
-  ]
 }
 
 source_set("libbase") {