Implement create attribute API functions for BTLE.

device/bluetooth/bluetooth_adapter_android.h

Index: device/bluetooth/bluetooth_adapter_android.h
diff --git a/device/bluetooth/bluetooth_adapter_android.h b/device/bluetooth/bluetooth_adapter_android.h
index c5ee32e57d057a7d2d5e14fc3c8d15d457c34965..c56914888a76c103184bb82e683116ed7a808146 100644
--- a/device/bluetooth/bluetooth_adapter_android.h
+++ b/device/bluetooth/bluetooth_adapter_android.h
@@ -85,6 +85,8 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapterAndroid final
       std::unique_ptr<BluetoothAdvertisement::Data> advertisement_data,
       const CreateAdvertisementCallback& callback,
       const CreateAdvertisementErrorCallback& error_callback) override;
+  BluetoothLocalGattService* GetGattService(
+      const std::string& identifier) const override;
 
   // Called when adapter state changes.
   void OnAdapterStateChanged(JNIEnv* env,