Further pep8 fixes

Fix the following issues in some files:
F401 'XXX' imported but unused
E123 closing bracket does not match indentation of opening bracket's
line
E126 continuation line over-indented for hanging indent
E128 continuation line under-indented for visual indent
E129 visually indented line with same indent as next logical line
H904  Wrap long lines in parentheses instead of a backslash

Partial-Bug: #1333290
Change-Id: Ic9b3a1e47fd24d2835f35f2ef71c4519908ff049
Merge "Further pep8 fixes"