mattermost update to 7.10.2-bb.1

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/mattermost/-/blob/7.10.2-bb.1/CHANGELOG.md

Package MR

big-bang/product/packages/mattermost!130 (merged)

For Issue

Closes big-bang/product/packages/mattermost#67 (closed)