Don't restrict local jinja2 variables to those that start with l_

Per a change in jinja2 2.9, local variables no longer are prefixed
with l_, so this updates AnsibleJ2Vars to pull in all locals (while
excluding some) regardless of name.

Fixes #20063

(cherry picked from commit 4d49b317929b86e1fc1b0cbace825ff73b372dc7)

test/integration/targets/template/tasks/main.yml

@@ -229,3 +229,17 @@
     that: 
       - "'templated_var_loaded' in lookup('file', '{{output_dir | expanduser }}/short.templated')"
       - "template_result|changed"
+
+# Create a template using a child template, to ensure that variables
+# are passed properly from the parent to subtemplate context (issue #20063)
+
+- name: test parent and subtemplate creation of context
+  template: src=parent.j2 dest={{output_dir}}/parent_and_subtemplate.templated
+  register: template_result
+
+- stat: path={{output_dir}}/parent_and_subtemplate.templated
+
+- name: verify that the parent and subtemplate creation worked
+  assert:
+    that:
+    - "template_result|changed"