Improve XML code highlighting

[Andre601]

The Code highlighting for the XML language is kinda odd looking, when compared to the desktop equivalent.

On mobile does it look like that right now (I use AMOLED Dark theme):

Meanwhile on Desktop (Windows) is it rendered like this:

It bothers me, that indend ending sections, like the </block> in our example, have a completely different text fill color, while all the other ones seem perfectly fine.
This should be corrected to have it more similar to the desktop version of the App.