Method 1
$ adb shell "setprop persist.sys.language zh; setprop persist.sys.country TW; setprop ctl.restart zygote"
Method 2
$ adb shell "setprop persist.sys.locale zh-TW; setprop ctl.restart zygote"
Reference:
https://stackoverflow.com/questions/21712205/change-device-language-via-adb