Safer noqa handling

"# flake8: noqa" was used in several files. This causes the
entire file to not be checked by flake8. This is unsafe, and
"# noqa" should be used only on those lines that require it.

E712 doesn't honor #noqa, so work around it by assigning True to a
variable.

Change-Id: I1ddd1c4f4230793f0560241e4559095cb4183d71
Merge "Safer noqa handling"