do not send empty application-vars (2600hz#4696)

fix route_resp_cavs spec

fix route_resp_cavs return

try using readlink for abs paths

.circleci/config.yml

@@ -79,25 +79,25 @@ jobs:
     # Test
     #   This would typically be a build job when using workflows, possibly combined with build
     # This is based on your 1.0 configuration file or project settings
-    - run: echo -e "\nexport CHANGED=\"$(git --no-pager diff --name-only HEAD origin/master -- applications core)\"\nexport CHANGED_SWAGGER=\"$(git --no-pager diff --name-only HEAD origin/master -- applications/crossbar/priv/api/swagger.json)\"\n" >> $BASH_ENV
+    - run: echo -e "\nexport CHANGED=$(git --no-pager diff --name-only HEAD origin/master -- applications core | xargs readlink -e)\nexport CHANGED_SWAGGER=$(git --no-pager diff --name-only HEAD origin/master -- applications/crossbar/priv/api/swagger.json | xargs readlink -e)\n" >> $BASH_ENV
     - run: echo $CHANGED
     - run: ./scripts/state-of-docs.sh || true
-    - run: ./scripts/code_checks.bash $($CHANGED)
+    - run: ./scripts/code_checks.bash $CHANGED
     - run: make fmt
     - run: JOBS="2" make
     - run: make code_checks
     - run: make app_applications
-    - run: ./scripts/validate-js.sh $($CHANGED)
+    - run: ./scripts/validate-js.sh $CHANGED
     - run: make apis
     - run: make docs
     - run: make validate-schemas
     - run: ./scripts/state-of-edoc.escript
     - run: make xref
     - run: make sup_completion
     - run: |
-        if [[ ! -z "$($CHANGED)" ]]; then
+        if [[ ! -z "$CHANGED" ]]; then
           make build-plt
-          TO_DIALYZE="$(echo $($CHANGED))" make dialyze
+          TO_DIALYZE="$CHANGED" make dialyze
         fi
     - run: make elvis
     - run: make build-ci-release

applications/ecallmgr/src/ecallmgr_fs_xml.erl

@@ -413,9 +413,10 @@ route_resp_ccvs(JObj) ->
 
 -spec route_resp_cavs(kz_json:object()) -> kz_types:xml_els().
 route_resp_cavs(JObj) ->
-    case kz_json:get_json_value(<<"Custom-Application-Vars">>, JObj) of
-        'undefined' -> [];
-        CAVs -> [action_el(<<"kz_multiset">>, route_cavs_list(kz_json:to_proplist(CAVs)))]
+    CAVs = kz_json:get_json_value(<<"Custom-Application-Vars">>, JObj, kz_json:new()),
+    case kz_json:to_proplist(CAVs) of
+        [] -> [];
+        Props -> [action_el(<<"kz_multiset">>, route_cavs_list(Props))]
     end.
 
 -spec route_ccvs_list(kz_term:proplist()) -> kz_term:ne_binary().