The answer is: the score will be four nil to Germany.
Seriously speaking, 'how many goals' is the subject of the question, not the object. Besides, the question is: 'Ile goli zostanie/będzie strzelonych w...?', and not 'Ile goli strzelą Niemcy?'.
REMEMBER:
'How many + plural noun + will be...?' is always the same.
How many cars will be damaged during the riots?
How many people will be injured during the riots?
If it was the object then the question would look like this:
How many goals WILL Germany (and Costa Rica) SCORE?