In some edge case when changing language the strings that are not translated are displayed in the previous language. (The case is when you choose on the app a language that has a parent, then any other language, and then the parent language.)

The reason is that in the code that manages the parent languages ​ makes an Object.assign that it shouldn't, and this causes the language strings from point 2 to overwrite the parent language strings

To reproduce:

1. Put the app in a language that has a parent language (e.g. 'en_us', whose parent is 'en').
2. Then change the language to any other language other than 'en' or 'en_us', for example the 'km' language.
3. Then change the language to 'en' (note, not 'en_us'). Strings from the language in point 2 are output. If you put it in 'en_us' it comes out fine, it only happens if you select the parent language.

The problem is caused by this line:

const mergedData = Object.assign(parentTranslations, data);

It seems changing it to this code fixes the problem, but we should test it properly:

const mergedData = {
    ...parentTranslations,
    ...data,
};