Minor layout/strings fixes and adjustments to the settings app

[Fs00]

This PR includes some fixes for a few minor issues I noticed on Weblate and while using the microG settings app:

• removed some leftover strings related to Mozilla Location Service and the old "custom service URL" dialog (I did this for all languages), so that people don't waste time translating them on Weblate
• replaced the Chinese colon character with the correct (English/latin) one in the games_leaderboards_score_label string
• tweaked the app location details screen so that preferences use all the available screen width (using app:iconSpaceReserved="false") and the hardcoded "Last reported location" string can be translated
• fixed the location service selection dialog so that the custom service URL can be set on small screens. Previously, part of the UI would have been cut when the screen wasn't tall enough, as you can see below:

custom_location_service_before.mp4

This is instead how it behaves now, after wrapping the layout in a ScrollView:

custom_location_service_after.mp4

In the layout, I've removed the <requestFocus /> tag because it made the ScrollView jump directly to the text field, potentially hiding the initial portion of text that the user is supposed to read.

• Last but not least, I've managed to find a way to allow preference titles to be multi-line by default, effectively restoring how they behaved before v0.3.1. This helps a lot with non-English languages that have long translated strings that cannot be easily shortened to a single line (Italian is one of them).
  Fixes Small UI regression in 0.3.1: preference titles are not multi-line anymore #2271