Add 2 retries for hybrid composition platform views. (#162400)

Trying to figure out if flake reports
https://github.com/flutter/flutter/issues/162362 and
https://github.com/flutter/flutter/issues/162363 are related to
https://github.com/flutter/flutter/issues/162310.

I was unable to reproduce locally:

```sh
dart tool/deflake.dart lib/platform_view/hybrid_composition_platform_view_main.dart
```

... so either the Mac Android emulators don't show this behavior, or
perhaps its just the slowness of CI VMs.

Either way, this should try taking a screenshot 2 more times (which has
built-in waits/sleeps), so if the problem persists that means there is a
more critical HC problem (the screen is _always_ drawn black sometimes)
versus a more transient problem (it "takes longer").