[release-branch.go1.13] crypto/cipher: require non-zero nonce size for AES-GCM

Also fix typo in crypto/cipher/gcm_test.go.

Updates #37118
Fixes #37417

Change-Id: I8544d1eeeb1f0336cebb977b8c5bfa5e4c5ad8c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/218500


Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
(cherry picked from commit 4e8badbb)
Reviewed-on: https://go-review.googlesource.com/c/go/+/220653


Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>