Use ISO country code "CN" for China

CH ->
CN

Author: ashie

src/keyboards/virtualkeyboardui-zh_CN.ext.json

@@ -295,7 +295,7 @@
     {
       "class": "LanguageSwitchKey"
     },
-    "CH",
+    "CN",
     {
       "x": 0.5,
       "c": "#cccccc",
@@ -582,7 +582,7 @@
     {
       "class": "LanguageSwitchKey"
     },
-    "CH",
+    "CN",
     {
       "x": 0.5,
       "c": "#cccccc",
@@ -865,7 +865,7 @@
     {
       "class": "LanguageSwitchKey"
     },
-    "CH",
+    "CN",
     {
       "x": 0.5,
       "c": "#cccccc",

src/keyboards/virtualkeyboardui-zh_CN.json

@@ -269,7 +269,7 @@
     {
       "class": "LanguageSwitchKey"
     },
-    "CH",
+    "CN",
     {
       "x": 0.5,
       "c": "#cccccc",
@@ -556,7 +556,7 @@
     {
       "class": "LanguageSwitchKey"
     },
-    "CH",
+    "CN",
     {
       "x": 0.5,
       "c": "#cccccc",
@@ -839,7 +839,7 @@
     {
       "class": "LanguageSwitchKey"
     },
-    "CH",
+    "CN",
     {
       "x": 0.5,
       "c": "#cccccc",

src/virtualkeyboardpinyin.h

@@ -26,7 +26,7 @@ enum class PinyinKeyboardMode {
 class PinyinKeyboard : public I18nKeyboard {
 public:
     KeyboardType type() const override { return KeyboardType::Pinyin; };
-    const char *label() const override { return "CH"; }
+    const char *label() const override { return "CN"; }
     const std::string languageCode() const override { return "zh_CN"; }
     void updateKeys() override;
     void switchMode();