Android 默认开启深色主题模式（暗夜模式）

/frameworks/base/core/res/res/values/config.xml

<!-- Control the default night mode to use when there is no other mode override set.

One of the following values (see UiModeManager.java):

0 - MODE_NIGHT_AUTO

1 - MODE_NIGHT_NO

2 - MODE_NIGHT_YES

tyd,lxd,def open night mode + UiModeManagerService.java

-->
<integer name="config_defaultNightMode">2</integer>

</resources>