Save a recording/screenshot to the uploaded xcresult when a Scenario test fails.
<img width="1052" alt="Screenshot 2023-12-14 at 6 34 47â¯PM" src="https://github.com/flutter/engine/assets/682784/c1294497-28f6-4400-b21c-da689a224dc4">
<img width="244" alt="Screenshot 2023-12-14 at 6 41 03â¯PM" src="https://github.com/flutter/engine/assets/682784/f769dd5f-a71b-4320-b9ef-64eac722166a">
No more errant spew as reported in https://github.com/flutter/engine/pull/19668 when this was originally turned off.
```
Test Case '-[StatusBarTest testTapStatusBar]' started.
t = 0.00s Start Test at 2023-12-14 18:20:34.207
...
t = 2.69s Synthesize event
t = 2.70s Find the StatusBar at {{0.0, 0.0}, {375.0, 20.0}}
t = 2.72s Find the StatusBar at {{0.0, 0.0}, {375.0, 20.0}}
t = 2.74s Find the StatusBar at {{0.0, 0.0}, {375.0, 20.0}}
t = 3.03s Wait for com.apple.springboard to idle
t = 3.43s Waiting 1.0s for "0,PointerChange.add,device=0,buttons=0,signalKind=PointerSignalKind.none" TextField to exist
t = 4.43s Checking `Expect predicate `exists == 1` for object "0,PointerChange.add,device=0,buttons=0,signalKind=PointerSignalKind.none" TextField`
t = 4.43s Checking existence of `"0,PointerChange.add,device=0,buttons=0,signalKind=PointerSignalKind.none" TextField`
t = 4.45s Capturing element debug description
t = 4.45s Checking existence of `"0,PointerChange.add,device=0,buttons=0,signalKind=PointerSignalKind.none" TextField`
/Volumes/Work/s/w/ir/cache/builder/src/out/ios_debug_sim/scenario_app/Scenarios/ScenariosUITests/StatusBarTest.m:37: error: -[StatusBarTest testTapStatusBar] : ((exists) is true) failed
t = 4.48s Tear Down
```
https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket/8761683198070320113/+/u/test:_Scenario_App_Integration_Tests__3_/stdout
Fixes https://github.com/flutter/flutter/issues/140192
[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style
e7d1af70f1