Unciv: 4.20.11

From Unciv: link to the original post

4.20.11

Fix double buttons for great people for constructing great improvements

Fixed custom file directories on Android

Approve values of 0 for certain mod constants in validator - By unciv-loof

By SomeTroglodyte:

• Fix black outlines for Stat symbols in notifications
• Fix TriggerUponLosingUnit
• Fix Android on screen keyboard show/hide
• Minor CPU optimization

Add 'Vegetation' to Marsh - By EmperorPinguin