Removed Kotpref and replaced it with PreferenceModel

app/src/main/java/com/topjohnwu/magisk/utils/XString.kt

@@ -18,4 +18,6 @@ fun StringBuilder.appendIf(condition: Boolean, builder: StringBuilder.() -> Unit
 fun Int.res(vararg args: Any): String {
     val resources: Resources by inject()
     return resources.getString(this, *args)
-}
+}
+
+fun String.trimEmptyToNull(): String? = if (isBlank()) null else this