Alarm time shown in horizon does not reflect system timezone

[Paul-Emile Element]

Title
-----
In the horizon GUI, alarms always show time in UTC by default.

Brief Description
-----------------
In the horizon GUI, alarms always show time in UTC by default, regardless of system time settings.

Severity
--------
Minor

Steps to Reproduce
------------------
-Install system with timezone != UTC
 (or change timezone using system modify command)
- generate an alarm
- observe alarm timestamp from CLI - it should reflect the system setting
- observe alarms in horizon - all timestamps are in UTC

Expected Behavior
------------------
By default (i.e., unless specifically changed in the GUI for the user)
the GUI should use system timezone for alarm display

Actual Behavior
----------------
in the gui, alarm time is displayed in UTC, regardless of the system settings

Reproducibility
---------------
100% Reproducible

System Configuration
--------------------
Any

Branch/Pull Time/Commit
-----------------------
Initial commit

Timestamp/Logs
--------------
N/A

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/621169
Committed: https://git.openstack.org/cgit/openstack/stx-config/commit/?id=516ed975aadb1c8eb44a9c4b25324e9b12b46026
Submitter: Zuul
Branch: master

commit 516ed975aadb1c8eb44a9c4b25324e9b12b46026
Author: Paul-Emile Element <email address hidden>
Date: Fri Nov 30 09:37:52 2018 -0500

    update horizon after timezone modification

    This commit modifies the sysinv conductor to update
    the horizon runtime manifests when the timezone is
    modified. This will allow the GUI to pick the
    new timezone settings without having to reboot
    the controller

    Closes-Bug: #1806051

    Change-Id: If24daaa97109d1020ec7f4ebdafebb5cda395ccb
    Signed-off-by: Paul-Emile Element <email address hidden>

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/621168
Committed: https://git.openstack.org/cgit/openstack/stx-upstream/commit/?id=76a033521e369c03a4e58261d8b27d04734dfede
Submitter: Zuul
Branch: master

commit 76a033521e369c03a4e58261d8b27d04734dfede
Author: Paul-Emile Element <email address hidden>
Date: Fri Nov 30 09:36:06 2018 -0500

    unset horizon TIME_ZONE to use system value instead

    The horizon configuration file has a value set for
    TIME_ZONE (set to UTC). This value is not available for users to
    modify and takes precedence over the system settings.
    The result is that the horizon GUI will show times in UTC
    regardless of the system settings

    This commit simple unsets the value so that the GUI
    uses the system values by default.

    Closes-Bug: #1806051

    Change-Id: If24daaa97109d1020ec7f4ebdafebb5cda395ccb
    Signed-off-by: Paul-Emile Element <email address hidden>