Split test targets that can run on windows.

PiperOrigin-RevId: 658619600

internal/platform/implementation/windows/BUILD

@@ -212,6 +212,7 @@ cc_library(
         "//chrome/chromeos/assistant/data_migration/lib:__pkg__",
         "//connections:__subpackages__",
         "//fastpair:__subpackages__",
+        "//internal/platform:__subpackages__",
         "//location/nearby:__subpackages__",
         "//presence:__subpackages__",
         "//sharing:__subpackages__",

internal/platform/implementation/windows/platform.cc

@@ -27,14 +27,13 @@
 
 #include <algorithm>
 #include <cstddef>
-#include <fstream>
 #include <memory>
-#include <optional>
 #include <sstream>
 #include <string>
 
 #include "absl/status/statusor.h"
 #include "absl/strings/string_view.h"
+#include "internal/platform/implementation/credential_storage.h"
 #include "internal/platform/implementation/http_loader.h"
 #include "internal/platform/implementation/shared/count_down_latch.h"
 #include "internal/platform/implementation/windows/atomic_boolean.h"
@@ -276,6 +275,11 @@ ImplementationPlatform::CreateBleV2Medium(api::BluetoothAdapter& adapter) {
   return std::make_unique<windows::BleV2Medium>(adapter);
 }
 
+std::unique_ptr<api::CredentialStorage>
+ImplementationPlatform::CreateCredentialStorage() {
+  return nullptr;
+}
+
 // TODO(b/184975123): replace with real implementation.
 std::unique_ptr<ServerSyncMedium>
 ImplementationPlatform::CreateServerSyncMedium() {