Removes unused import statements

Updates tox.ini to remove suppressed F401 standard.

Updates the code files containing unused import statements

Change-Id: Ib44bd1509fdb17f457a205f9e62caf85cebee830
Closes-Bug: #1257267
Updates tox.ini to remove suppressed H401.

Updates the code files containing H401 bug.

Change-Id: Ib0511a9447aa676cef3af7cdfcd9fd92748283b7
Closes-Bug: #1257294