Fix License Headers and Enable Gating on H102

Add ASLv2 headers to files that were missing it.

fixes bug #1211587

Change-Id: Iede918e1ce84993cee4ecbb2d9c2606627fa412e
Fix and enable gating on H302: only import modules

Fixes non-module imports and enables gating on H302 in flake8

Change-Id: I366b0ca622d5185732c6c755f8724efb8bbc80f7
Merge "Fix License Headers and Enable Gating on H102"
Merge "Fix and enable gating on H302: only import modules"
Fix and enable gating on F841

F841 local variable is assigned to but never used

Change-Id: I4b54489386deb655821192b4ec1e9c0ea596a9b7
Merge "Fix and enable gating on F841"