Consolidate edxapp update assets scripts.

The asset compilation scripts edxapp-update-assets-lms and
edxapp-update-assets-cms duplicate a lot of work between them. Running
webpack twice also seems to cause an intermittent error where the
second build results in a different bundle hash than the first.

It is possible to run "paver update_assets" without specifying "lms" or
"cms", in which case it just compiles it all at the same time. This
removes the duplicate invocations of webpack and should speed the build
overall.

playbooks/roles/edxapp/defaults/main.yml

@@ -887,7 +887,6 @@ edxapp_aa_command: "{% if EDXAPP_SANDBOX_ENFORCE %}aa-enforce{% else %}aa-compla
 edxapp_helper_scripts:
     - edxapp-migrate
     - edxapp-runserver
-    - edxapp-update-assets
     - edxapp-shell
 
 edxapp_environment_default:

playbooks/roles/edxapp/tasks/service_variant_config.yml

@@ -108,6 +108,16 @@
     - install
     - install:configuration
 
+- name: create script to compile and update assets
+  template:
+    src: "edx/bin/edxapp-update-assets.j2"
+    dest: "{{ COMMON_BIN_DIR }}/edxapp-update-assets"
+    owner: "{{ edxapp_user }}"
+    mode: 0755
+  tags:
+    - install
+    - install:configuration
+
 # migrate when the migrate user is overridden in extra vars
 - name: migrate
   command: "{{ COMMON_BIN_DIR }}/edxapp-migrate-{{ item }}"
@@ -139,10 +149,9 @@
     - assets
 
 # Gather assets using paver if possible
-- name: "gather {{ item }} static assets with paver"
-  command: "{{ COMMON_BIN_DIR }}/edxapp-update-assets-{{ item }}"
-  when: celery_worker is not defined and not devstack and item != "lms-preview"
-  with_items: "{{ service_variants_enabled }}"
+- name: "gather static assets with paver"
+  command: "{{ COMMON_BIN_DIR }}/edxapp-update-assets"
+  when: celery_worker is not defined and not devstack
   tags:
     - gather_static_assets
     - assets

playbooks/roles/edxapp/templates/edx/bin/edxapp-update-assets-lms.j2

-{% include "edxapp_common.j2" %}
-
-sudo -E -H -u {{ edxapp_user }} env "PATH=$PATH" {{ edxapp_venv_bin }}/paver update_assets lms --settings $EDX_PLATFORM_SETTINGS

playbooks/roles/edxapp/templates/edx/bin/edxapp-update-assets-cms.j2 → playbooks/roles/edxapp/templates/edx/bin/edxapp-update-assets.j2

 {% include "edxapp_common.j2" %}
 
-sudo -E -H -u {{ edxapp_user }} env "PATH=$PATH" {{ edxapp_venv_bin }}/paver update_assets cms --settings $EDX_PLATFORM_SETTINGS
+sudo -E -H -u {{ edxapp_user }} env "PATH=$PATH" {{ edxapp_venv_bin }}/paver update_assets --settings $EDX_PLATFORM_SETTINGS