希望macaca java api增加一个获取手机分辨率的方法。现在getWindowSize取到的是窗口大小

截屏获取到的图像是原始分辨率的图像，而getWindowSize取到的是窗口大小，。我这边有个需求是获取屏幕指定一个位置的图像，无法根据windowSize直接去计算位置。希望家一个获取分辨率的方法

* **Macaca Version**:
2.0.30
* **Macaca Doctor Logs**:

* **Operate System**:
Mac
* **Programming Language**:
java

Start by locating the Java API entry point for getWindowSize and compare its reported window dimensions with the original screenshot resolution described in the issue. Determine where a separate screen-resolution method belongs and verify that it returns the dimensions needed for position calculations. Done means the Java API exposes that resolution distinctly from window size, with an appropriate test.

Written by the indexing model from the issue text.