CSR-222: add back button to vehicle-make layout

src/layouts/vehicle-make/vehicle-make.vue

@@ -4,7 +4,13 @@
     <div class="select-car">
       <div class="select-car-form rounded text-center">
         <vehicleBanner :vehicleImageSrc="vehicleBannerWidget.GenericVehicleImage" />
-        <funnelSubHeader :text="pageHeaderWidgets.HeaderText" class="Header" />
+        <funnelSubHeader 
+            :text="pageHeaderWidgets.HeaderText"
+            :hasBackButton="true"
+            backButtonAccessibleText="Change Vehicle Year"
+            :backButtonAction="backButtonAction"
+            class="Header" 
+        />
         <makeQuestion v-model="selectedMake" ref="makeQuestion" />
       </div>
     </div>
@@ -60,6 +66,13 @@ export default {
     });
   },
 
+  methods: {
+    backButtonAction: function () {
+      // route to move backwards
+      this.$router.navigate(this.navigationScenarios.CLICKED_BACK, this.$route);
+    }
+  },
+
   watch: {
     selectedMake(make) {
       this.$store.commit(this.storeMutations.UPDATE_MAKE, make);