Revert "[execute_process] emulate_tty configurable and defaults to true (ros2#265)" (ros2#276)

This reverts commit 561a23a.

Author: wjwwood

launch/examples/disable_emulate_tty_counters.py

@@ -38,8 +38,6 @@
 from osrf_pycommon.process_utils import async_execute_process
 from osrf_pycommon.process_utils import AsyncSubprocessProtocol
 
-import yaml
-
 from .emit_event import EmitEvent
 from .opaque_function import OpaqueFunction
 from .timer_action import TimerAction
@@ -97,7 +95,6 @@ def __init__(
             'sigterm_timeout', default=5),
         sigkill_timeout: SomeSubstitutionsType = LaunchConfiguration(
             'sigkill_timeout', default=5),
-        emulate_tty: bool = True,
         prefix: Optional[SomeSubstitutionsType] = None,
         output: Text = 'log',
         output_format: Text = '[{this.name}] {line}',
@@ -176,8 +173,6 @@ def __init__(
             as a string or a list of strings and Substitutions to be resolved
             at runtime, defaults to the LaunchConfiguration called
             'sigkill_timeout'
-        :param: emulate_tty emulate a tty (terminal), defaults to
-            the LaunchConfiguration called 'emulate_tty'
         :param: prefix a set of commands/arguments to preceed the cmd, used for
             things like gdb/valgrind and defaults to the LaunchConfiguration
             called 'launch-prefix'
@@ -216,7 +211,6 @@ def __init__(
         self.__shell = shell
         self.__sigterm_timeout = normalize_to_list_of_substitutions(sigterm_timeout)
         self.__sigkill_timeout = normalize_to_list_of_substitutions(sigkill_timeout)
-        self.__emulate_tty = emulate_tty
         self.__prefix = normalize_to_list_of_substitutions(
             LaunchConfiguration('launch-prefix', default='') if prefix is None else prefix
         )
@@ -583,16 +577,6 @@ async def __execute_process(self, context: LaunchContext) -> None:
             self.__logger.info("process details: cmd=[{}], cwd='{}', custom_env?={}".format(
                 ', '.join(cmd), cwd, 'True' if env is not None else 'False'
             ))
-        try:
-            emulate_tty = yaml.safe_load(
-                context.launch_configurations['emulate_tty']
-            )
-            if type(emulate_tty) is not bool:
-                raise TypeError('emulate_tty is not boolean [{}]'.format(
-                    type(emulate_tty)
-                ))
-        except KeyError:
-            emulate_tty = self.__emulate_tty
         try:
             transport, self._subprocess_protocol = await async_execute_process(
                 lambda **kwargs: self.__ProcessProtocol(
@@ -602,7 +586,7 @@ async def __execute_process(self, context: LaunchContext) -> None:
                 cwd=cwd,
                 env=env,
                 shell=self.__shell,
-                emulate_tty=emulate_tty,
+                emulate_tty=False,
                 stderr_to_stdout=False,
             )
         except Exception: