Do not kill emulators when testing (#47030)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/47030

Looking at the videos from the E2E tests, it seems that the tests are pretty reliable aside from the first one that often fail. And it looks like it is failing not because the test is wrong, but because maestro hits some sort of timeout and kills the test sooner.

With these changes we are:
- giving more time to maestro to run
- not killing the emulator anymore

Killing and restarting the simulator was making this problem workse, because a newly started simulator required more time to boots and to work properly

## Changelog:
[Internal] - stop killing simulators and increase timeouts

Reviewed By: cortinico

Differential Revision: D64398111

fbshipit-source-id: 17b107fee24d0fbd4897212c1907be3761e337ab