How to reproduce on Windows OS:
1. Go to Control Panel->Clock and Region->Region->Additional settings
2. Make sure that Decimal symbol is ','(comma)
3. Open user-submitted project (InputFieldBug.zip)
4. Try using comma as decimal separator

Expected result: Unity respects the current culture and uses comma as decimal separator
Actual result: Unity uses '.'(period) as decimal separator

Reproducible with: 2017.1.4p2, 2017.2.3p2, 2017.4.6f1, 2018.1.7f1, 2018.2.0b8, 2018.3.0a3

Notes:

• One can use comma while assigning InputField value in the inspector (this introduces inconsistency between InputField input validation and InputField inspector validation)