Cleanup Nova console proxy git repos before updating it

This fix removes /usr/share/spice-html5 and /usr/share/novnc
before updating it in order to prevent git clone issues where
simple git resets seem not clean enough.

Change-Id: I8abdffc2377b68fc40a6a9b678f24eb99a0bc537
Closes-Bug: #1585331

releasenotes/notes/nova-console-proxy-git-cleanup-cdeffd3f0d040275.yaml

@@ -0,0 +1,8 @@
+---
+upgrade:
+  - Cleanup tasks are added to remove the nova console git
+    directories ``/usr/share/novnc`` and ``/usr/share/spice-html5``,
+    prior to cloning these inside the nova vnc and spice
+    console playbooks. This is necessary to guarantee
+    that local modifications do not break git clone
+    operations, especially during upgrades.

tasks/nova_console_novnc_install.yml

@@ -13,6 +13,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+- name: Remove old git directory
+  file:
+    path: "/usr/share/novnc"
+    state: "absent"
+  tags:
+    - nova-install
+    - nova-novnc-git
+
 - name: Get package from git
   git:
     repo: "{{ nova_novncproxy_git_repo }}"

tasks/nova_console_spice_install.yml

@@ -45,6 +45,13 @@
     - nova-apt-packages
     - nova-spice-apt-packages
 
+- name: Remove old git directory
+  file:
+    path: "/usr/share/spice-html5"
+    state: "absent"
+  tags:
+    - nova-spice-git
+
 - name: Get package from git
   git:
     repo: "{{ nova_spicehtml5_git_repo }}"