Google takes child porn really serious and suspends and even terminates accounts for that reason.
Although it was not your fault that the person sent child porn to you as it does happen.
Google actually as software in place that detects child porn so they can easily detect it and close an account down.
Google has so much software and scripts that are available to them which does not even require a person to look at or detect something.
If the Google Account was simply suspended them sometimes after 24 hours the google account is reactivated.
But if it's actually terminated then the Google Account is permanently banned.
The only way then to get a Google account is to sign up for a new Google Account.
From what Google Support says about reactivating a Suspended Google Account.
At the top right, click Reactivate. Reactivate within a users column. If the Reactivate option isn't available, you must wait up to 24 hours before the limits are reset automatically. During this time, the user can still use other Google services.
You may have to wait a bit and try sending another request although it still may be denied.
You have to be real careful about child pictures because child porn can get you into trouble even though I believe that it was just the other persons fault and not yours.
Heck I even had naked photos of my nephew sent to me even though I told my sister not to send those photos because it was illegal and wrong.
But I have not had a Google Account disabled.