Unciv: 4.15.20

From Unciv: link to the original post

4.15.20

Fixed autosave crashes when saving to external files on some Android devices

Modding:

• Replaced semi-working policy branch restriction with countable + Unavailable
• Negative stat percentages from buildings displayed properly in city screen.

Experimental UI animations change. - By k-oa

By EmperorPinguin:

• Add pillage yield uniques
• Add game progress modifier

By SomeTroglodyte:

• Minor refactor: Save/Load game loading image uses LoadingImage
• Mod download robustness