Function example_configure_stdin_stdout() was used for simple UART I/O
operation in CI to enter test env configuration (wifi ssid, IPs, etc).
It could be called multiple times, but didn't handle the situation where
we install UART interrupt from multiple source (e.g. in ICMP tests,
where we first need to enter wifi credentials of test AP and then we
start ping-cmd console to handle ping commands)
- Newlib uses significantly more stack space when printing to an unbuffered stream
- For examples tests, disabling buffering on stdout is not really required
This issue was found during one of the OTA example test failure, root cause
being stack overflow in `esp_event` task.