Add enable_ip_forwarding option to azure_rm_networkinterface; Fixes #43276 (#43335)

* Merge again trickily similar Accelerated networking and IP forwarding

* Add type to enable_ip_forwarding documentation

* Fix merge error

* auth to auto

* azure_rm_networkinterface: remove auth_source from tests

* azure_rm_networkinterface: remove spurious auth_source from test

* azure_rm_networkinterface: Revert formatting on test

* azure_rm_networkinterface: Correct indentation

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

@@ -143,7 +143,7 @@
           primary: True
           public_ip_allocation_method: Static
         - name: ipconfig1
-          public_ip_name: testnic003
+          public_ip_name: "tn{{ rpfx }}3"
   register: output
   check_mode: yes
 
@@ -168,7 +168,7 @@
           primary: True
           public_ip_allocation_method: Static
         - name: ipconfig1
-          public_ip_name: testnic003
+          public_ip_name: "tn{{ rpfx }}3"
           load_balancer_backend_address_pools:
           - "{{ lb.state.backend_address_pools[0].id }}"
           - name: backendaddrpool1
@@ -197,7 +197,7 @@
           primary: True
           public_ip_allocation_method: Static
         - name: ipconfig1
-          public_ip_name: testnic003
+          public_ip_name: "tn{{ rpfx }}3"
           load_balancer_backend_address_pools:
           - "{{ lb.state.backend_address_pools[0].id }}"
           - name: backendaddrpool1
@@ -219,7 +219,7 @@
       subnet: "tn{{ rpfx }}"
       ip_configurations:
         - name: ipconfig1
-          public_ip_name: testnic003
+          public_ip_name: "tn{{ rpfx }}3"
           load_balancer_backend_address_pools:
           - "{{ lb.state.backend_address_pools[0].id }}"
           - name: backendaddrpool1
@@ -292,12 +292,71 @@
 - assert:
     that:
       - not output.state.enable_accelerated_networking
+      - output.changed
 
 - name: Delete AN NIC
   azure_rm_networkinterface:
       resource_group: "{{ resource_group }}"
       name: "tn{{ rpfx }}an"
       state: absent
+  register: output
+
+- assert:
+    that:
+      - output.changed
+
+- name: NIC with IP forwarding networking enabled
+  azure_rm_networkinterface:
+    resource_group: "{{ resource_group }}"
+    name: "tn{{ rpfx }}ipf"
+    virtual_network: "{{ vn.state.id }}"
+    subnet: "tn{{ rpfx }}"
+    enable_ip_forwarding: True
+  register: output
+
+- assert:
+    that:
+      - output.state.enable_ip_forwarding
+      - output.changed
+
+- name: NIC with IP forwarding enabled (check idempotent)
+  azure_rm_networkinterface:
+    resource_group: "{{ resource_group }}"
+    name: "tn{{ rpfx }}ipf"
+    virtual_network: "{{ vn.state.id }}"
+    subnet: "tn{{ rpfx }}"
+    enable_ip_forwarding: True
+  register: output
+
+- assert:
+    that:
+      - output.state.enable_ip_forwarding
+      - not output.changed
+
+- name: Disable (previously enabled) IP forwarding
+  azure_rm_networkinterface:
+    resource_group: "{{ resource_group }}"
+    name: "tn{{ rpfx }}ipf"
+    virtual_network: "{{ vn.state.id }}"
+    subnet: "tn{{ rpfx }}"
+    enable_ip_forwarding: False
+  register: output
+
+- assert:
+    that:
+      - not output.state.enable_ip_forwarding
+      - output.changed
+
+- name: Delete IP forwarding NIC
+  azure_rm_networkinterface:
+    resource_group: "{{ resource_group }}"
+    name: "tn{{ rpfx }}ipf"
+    state: absent
+  register: output
+
+- assert:
+    that:
+      - output.changed
 
 - name: Delete the NIC (check mode)
   azure_rm_networkinterface: