example showcase patches: use default instead of game mode for desktop

[mockersf]

Objective

• After Fix perf degradation on web builds #11227, example showcase timeouts
• ReactiveLowPower now can wait indefinitely depending on "platform specifics"

Solution

• Patch desktop mode in example showcase to use default mode which is always Continuous

[nicopap]

FYI #11227 didn't change the wait behavior, it just added a comment describing the already-existing behavior, which predates #11227 and #10702.

However, #11227 did change the update logic to rely on RedrawRequested window events. I'm not sure if this works with whatever we are using for testing.