Support editing previous revisions

Authored by MtDu on Sat, Aug 12, 8:42 PM.

Description

Support editing previous revisions

Before, when a user attempted to edit a previous revision, an error
was thrown. This change adds support for attempting this action.

Bug: T173224
Change-Id: I8f1c1cde19391457a0fa71f082c5269fc1ddf4d9

Details