mattermost update to 7.10.2-bb.2

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/mattermost/-/blob/7.10.2-bb.2/CHANGELOG.md

Package MR

big-bang/product/packages/mattermost!128 (merged)

For Issue

Closes https://repo1.dso.mil/big-bang/product/packages/mattermost/-/issues/70