Roll forward to cl/328359974

Change-Id: Id081e9ee4e78fc51e01992c1f2db3b9e32b3e776

cpp/platform_v2/api/bluetooth_adapter.h

@@ -63,6 +63,9 @@ class BluetoothAdapter {
   virtual std::string GetName() const = 0;
   // https://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#setName(java.lang.String)
   virtual bool SetName(absl::string_view name) = 0;
+
+  // Returns BT MAC address assigned to this adapter.
+  virtual std::string GetMacAddress() const = 0;
 };
 
 }  // namespace api