No it is not discriminating against men. It is fighting existing discrimination against women. Women are already discriminated against in these fields, to try to stop that we have to encourage them to participate. Because it is Really Hard to join an industry or field where you are discriminated against.
I can't emphasise enough that this is not discrimination.
Discrimination is the "unjust or prejudicial treatment of different categories of people."
Google only has finite resources. Diverting them to assist the oppressed class (women) is not discrimination against the dominant class (men). It is simply a way to correct for existing discrimination against women.
As someone who takes these kinds of larger social issues fairly seriously, and supports many efforts to correct the long lasting effects of discrimination, I think viewing this issue in such a binary fashion(that is that women as a class are oppressed and men are the oppressors) is both incorrect and unhelpful to the cause you seem to be supporting. Privilege, oppression, and discrimination exist over multiple overlapping spectrums. The notion that in a country like the US white women(due to their being women) are somehow oppressed by black men(due to their being men) is both incorrect, and quite frankly, somewhat insulting. You will not win any allies to your cause by framing these very important issues in such a binary, and unnuanced way.
