added linux feature flag to enable 5ghz hotspot

internal/platform/implementation/linux/linux_flags.cc

@@ -0,0 +1,30 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "internal/platform/implementation/linux/linux_flags.h"
+
+#include <atomic>
+
+namespace nearby::linux {
+namespace {
+
+std::atomic_bool kEnable5GhzHotspot = true;
+
+}  // namespace
+
+bool Is5GhzHotspotEnabled() { return kEnable5GhzHotspot.load(); }
+
+void Set5GhzHotspotEnabled(bool enabled) { kEnable5GhzHotspot.store(enabled); }
+
+}  // namespace nearby::linux