build-unit-test-docker: Fix sudo umask
build-unit-test-docker: Fix sudo umask

We don't want our install invocations to generate files that the user is
unable to modify. Setting the umask to 000 means that any files created
during our sudo invocations will be user modifiable.

Change-Id: Ibb452995037116b4e9df13d85db746c198fece0c
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/openbmc-build-scripts,openbmc/openbmc-build-scripts