Flake8: Fix E126 and E127

Fix these issues and enable E126 and E127:
E126 continuation line over-indented for hanging indent
E127 continuation line over-indented for visual indent

Also fix a few occurences in the touched files of:
E128 continuation line under-indented for visual indent
H405  multi line docstring summary not separated with an empty line

Partial-Bug: #1333290
Change-Id: If822401fc7e1db49d595a0736a0dff8e00dfd217