Android U 如何修改WiFi RSSI 信号格数显示

下面便是AOSP中WiFi RSSI 控制的地方（config_wifiRssiLevelThresholds），但是这里是在/packages/modules/Wifi/路径下面，无法修改。所以需要overlay 这个参数来进行修改。

为什么/packages/modules/Wifi/路径下无法修改，请check下面文档
https://blog.youkuaiyun.com/NiHuiShenMo/article/details/136879813?spm=1001.2014.3001.5501

<!--/packages/modules/Wifi/service/ServiceWifiResources/res/values/config.xml -->

    <!--
    Controls the mapping between RSSI and RSSI levels.

    RSSI                                    RSSI Level
    (-infinity, thresholds[0])                       0
    [threshold[0], threshold[1])                     1
    [threshold[1], threshold[2])                     2
    ...                                            ...
    [threshold[len-2], threshold[len-1])         len-1
    [threshold[len-1], +infinity)                  len

    where:
        [a, b) is the range of integers `n` such that a <= n < b
        `threshold[i]` represents the i'th element of the config_wifiRssiLevelThresholds array
        and `len` is the length of the config_wifiRssiLevelThresholds array.
    -->
    <integer-array translatable="false" name="config_wifiRssiLevelThresholds">
                         <!-- RSSI                RSSI Level -->
        <item>-88</item> <!-- (-infinity, -88)             0 -->
        <item>-77</item> <!-- [-88, -77)                   1 -->
        <item>-66</item> <!-- [-77, -66)                   2 -->
        <item>-55</item> <!-- [-66, -55)                   3 -->
                         <!-- [-55, +infinity)             4 -->
    </integer-array>

Rssi分5格（-infinity, -88）（-88, -77）（-77, -66）（-66, -55）（-55, +infinity）
可以根据自己的需求进行修改，一般在-95dbm就扫描不到AP了。