Removes calls to mock.patch.stopall in unit tests

Removes unnecessary calls to mock.patch.stopall
in individual unit tests since it is now
automatically called from the base test case.

Closes-Bug: #1291130
Change-Id: Ia8e82d6a9a9bc9bd5f48146c1be53069ff1cdb01
Merge "Removes calls to mock.patch.stopall in unit tests"