Fix prompt mismatch issue for ios (#47004)

* Fix prompt mismatch issue for ios

Fixes #40884 #44463

*  If the command prompt is matched check if data is
   still pending to be read from buffer.
*  This fix adds a new timer `buffer_read_timeout`
   which will be trigerred after command prompt
   is matched and data is attempted to be read from channel.
   If not data is present of channel the timer will expire
   and response we be returned to calling function.

* Fix unit test failure

* Update to make buffer timeout float

* Update doc and fix review comment

* Fix CI issues

* Update doc

* Fix review comments

* Fix review comments

docs/docsite/rst/network/user_guide/network_debug_troubleshooting.rst

@@ -656,3 +656,38 @@ Example Ansible inventory file
    This is done to prevent secrets from leaking out, for example in ``ps`` output.
 
    We recommend using SSH Keys, and if needed an ssh-agent, rather than passwords, where ever possible.
+
+Miscellaneous Issues
+====================
+
+
+Intermittent failure while using ``network_cli`` connection type
+----------------------------------------------------------------
+
+If the command prompt received in response is not matched correctly within
+the ``network_cli`` connection plugin the task might fail intermittently with truncated
+response or with the error message ``operation requires privilege escalation``.
+Starting in 2.7.1 a new buffer read timer is added to ensure prompts are matched properly
+and a complete response is send in output. The timer default value is 0.2 seconds and
+can be adjusted on a per task basis or can be set globally in seconds.
+
+Example Per task timer setting
+
+.. code-block:: yaml
+
+  - name: gather ios facts
+    ios_facts:
+      gather_subset: all
+    register: result
+    vars:
+      ansible_buffer_read_timeout: 2
+
+
+To make this a global setting, add the following to your ``ansible.cfg`` file:
+
+.. code-block:: ini
+
+   [persistent_connection]
+   buffer_read_timeout = 2
+
+This timer delay per command executed on remote host can be disabled by setting the value to zero.