test: make descent FlightODE option contract explicit

[suhaslord]

First evidence-backed migration slice from the OpenMDAO#1251 option-default control plane.

Runtime tracing across the two-DOF ODE tests showed that the inline get_option_defaults() passed directly to the descent FlightODE reads exactly one inherited value: Settings.VERBOSITY. Its metadata default is Verbosity.BRIEF.

Change

• replaces that inline global-default object with an explicit one-key AviaryValues contract for Settings.VERBOSITY
• leaves the separate builder-heavy options object alone for now; tracing shows that object feeds downstream builders that read a much larger option surface
• regenerates the repository migration baseline

Ratchet movement

• repository: 86 → 85 get_option_defaults() calls
• two-DOF mission domain: 13 → 12

This is intentionally small in code size but not guessed: it is the first conversion produced by the static + runtime dependency framework, and it demonstrates the repeatable migration loop before tackling the builder-heavy call sites.