This class is a lightweight entity containing a requirement type (e.g.
code-owners, all-checks-pass, etc...) and a textual description of the
requirement named "fallbackText". This class is only referenced from
SubmitRecord which contains a list of these requirements. Renaming to
SubmitLegacyRequirement to reserve SubmitRequirement for the new
composable submit requirements.
Few plugins need to adapt to this change (code-owners, checks,
startblock, simple-submit-rules).
Change-Id: Ib55038627c95ece82a7eddd64e317183f1752487
(cherry picked from commit 2c3b4754e21de7250d24c11f48318139d4d1c10b)
f61983a59c