Give IncludedFile more context via ansible_search_path (#50045)

* Give IncludedFile more context via ansible_search_path to template lookups. Fixes #49969

* Update units

test/integration/targets/include_import/parent_templating/playbook.yml

@@ -0,0 +1,11 @@
+# https://github.com/ansible/ansible/issues/49969
+- hosts: localhost
+  gather_facts: false
+  tasks:
+    - include_role:
+        name: test
+        public: true
+
+    - assert:
+        that:
+          - included_other is defined

test/integration/targets/include_import/parent_templating/roles/test/tasks/localhost.yml

@@ -0,0 +1 @@
+- include_tasks: other.yml

test/integration/targets/include_import/parent_templating/roles/test/tasks/main.yml

@@ -0,0 +1 @@
+- include_tasks: "{{ lookup('first_found', inventory_hostname ~ '.yml') }}"

test/integration/targets/include_import/parent_templating/roles/test/tasks/other.yml

@@ -0,0 +1,2 @@
+- set_fact:
+    included_other: true

test/integration/targets/include_import/runme.sh

@@ -90,3 +90,7 @@ ansible-playbook run_once/playbook.yml "$@"
 # https://github.com/ansible/ansible/issues/48936
 ansible-playbook -v handler_addressing/playbook.yml 2>&1 | tee test_handler_addressing.out
 test "$(egrep -c 'include handler task|ERROR! The requested handler '"'"'do_import'"'"' was not found' test_handler_addressing.out)" = 2
+
+# https://github.com/ansible/ansible/issues/49969
+ansible-playbook -v parent_templating/playbook.yml 2>&1 | tee test_parent_templating.out
+test "$(egrep -c 'Templating the path of the parent include_tasks failed.' test_parent_templating.out)" = 0