Increase testing backchannel waiting time to 50ms (project-chip#38788)

* Increase testing backchannel waiting time to 50ms

The merge of project-chip/connectedhomeip@0b7c1c5 now leads to centralized backchannel communication via the file socket which is great, but the very short waiting time of 1ms is a bit short for all cases to reduce flaky tests - especially also when matter.js is used as DuT, so increasing that wait time to 50ms at least should give. more stability for the tests

* 100ms is better and more reliable

* 20ms should also be robust enough

* update comment as requested

* upgrade to 50ms

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Co-authored-by: Andrei Litvin <[email protected]>

Author: Apollon77

src/python_testing/matter_testing_infrastructure/chip/testing/matter_testing.py

@@ -1105,7 +1105,8 @@ def write_to_app_pipe(self, command_dict: dict, app_pipe_prefix: Optional[str] =
                 app_pipe.write(json.dumps(command_dict) + "\n")
 
             # TODO(#31239): remove the need for sleep
-            sleep(0.001)
+            # This was tested with matter.js as being reliable enough
+            sleep(0.05)
         else:
             logging.info(f"Using DUT IP address: {dut_ip}")