android studio 'ctrl+/'注释掉代码的时候，双斜线总是从第一列开始，不能缩进，正确的设置项是：
Settings → Editor → Code Style → JAVA. Select "Code Generation" tab：
然后把"Line comment at first column"去掉，即可，注意要找到"Code Generation" tab页才行，不能是其他的。
参考：https://stackoverflow.com/questions/40113105/android-studio-wrong-line-comment-indentation
You have to go to Settings → Editor → Code Style → JAVA. Select "Code Generation" tab.
Deselect "Line comment at first column" option, on Comment Code section.
