core-ktx: It is impossible to use shared preferences delegates in local variables

[rwqwr]

It is not possible to use delegates in local variables.

    fun changeValue(newValue: String) {
        var value: String by preferences.string("key")
        value = newValue
        println(value)
    }

The reason is the use of a non-null object type to which the delegated property belongs, i.e. T generic type in the ReadWriteProperty class. I noticed this in the core extensions, but it might be appropriate in other delegates as well. If you want, I can create a MR with the fixes.

[osipxd]

MR is welcome!