allow grep style keybindings for `counsel-ag`

[wbolster]

is there a reason that counsel-ag does not define :keymap counsel-git-grep-map? it would allow C-l to recenter (i.e. display buffer at right location) during search. this works for counsel-grep but not for counsel-ag, and adding this line seems to work fine.

[abo-abo]

Thanks.

[abo-abo]

You can now also use M-q in counsel-ag.