Fix non-custom Total stage in VSA

What does this MR do?

This MR fixes the uneditable non-custom Total stage in value stream analytics. The Total stage was removed from VSA a few releases ago thus we need to make sure that the persisted Total stages have the custom flag set to true.

After checking the production DB, we have 3 occurrences of this bug, so we expect 3 record updates only.

How to reproduce it:

1. Go to https://gitlab.com/groups/gitlab-org/-/analytics/value_stream_analytics
2. Select 'default' from the dropdown.
3. Click the "Edit" button.
4. Scroll down and notice the "Total" stage is not editable.

Migration

UP

== 20210601073400 FixTotalStageInVsa: migrating ===============================
== 20210601073400 FixTotalStageInVsa: migrated (0.0116s) ======================

DOWN

== 20210601073400 FixTotalStageInVsa: reverting ===============================
== 20210601073400 FixTotalStageInVsa: reverted (0.0000s) ======================

Queries

The table contains 2000 rows and we expect to update 3 rows only.

EachBatch query:

SELECT "analytics_cycle_analytics_group_stages"."id"
FROM "analytics_cycle_analytics_group_stages"
WHERE "analytics_cycle_ana
lytics_group_stages"."id" >= 2167
ORDER BY "analytics_cycle_analytics_group_stages"."id" ASC
LIMIT 1
OFFSET 100;

Plan: https://explain.depesz.com/s/zPng

Update query:

UPDATE "analytics_cycle_analytics_group_stages"
SET "custom" = TRUE
WHERE "analytics_cycle_analytics_group_stages"."id" >= 1745
  AND "analytics_cycle_analytics_group_stages"."id" < 1901
  AND "analytics_cycle_analytics_group_stages"."name" = 'Total'
  AND "analytics_cycle_analytics_group_stages"."custom" = FALSE;

Plan: https://explain.depesz.com/s/Ssl8

Does this MR meet the acceptance criteria?

Conformity

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• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
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• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team