fix: apply block image placeholder url

Author: gabrieloliveirapinto

frontend/express/public/javascripts/countly/vue/components/content.js

@@ -774,6 +774,8 @@
         template: CV.T('/javascripts/countly/vue/templates/content/UI/content-sidebar-input.html')
     }));
 
+    const DEFAULT_LIST_BLOCK_IMAGE_PLACEHOLDER_URL = '/content/images/fullscreenPlaceholderImage.png';
+
     Vue.component('cly-content-block-list-input', countlyVue.components.create({
         props: {
             blockInputs: {
@@ -788,6 +790,19 @@
             'input'
         ],
 
+        computed: {
+            mappedBlockInputs() {
+                return this.blockInputs.map(block => {
+                    return block.map(blockInput => ({
+                        ...blockInput,
+                        ...(blockInput.id.includes('image') && !blockInput.value) && {
+                            value: DEFAULT_LIST_BLOCK_IMAGE_PLACEHOLDER_URL
+                        }
+                    }));
+                });
+            }
+        },
+
         methods: {
             onAddAsset(payload) {
                 this.$emit('add-asset', payload);

frontend/express/public/javascripts/countly/vue/templates/content/UI/content-block-list-input.html

@@ -1,7 +1,6 @@
 <div class="cly-content-block-list-input">
-  <!-- v-tooltip.right="step.componentTooltip" -->
   <el-collapse
-    v-for="(block, blockIndex) in blockInputs"
+    v-for="(block, blockIndex) in mappedBlockInputs"
     :key="`list-block-${blockIndex}`"
     class="cly-content-block-list-input__list-block"
   >
@@ -12,7 +11,7 @@
               <img
                   class="cly-content-block-list-input__list-block-header-display-icon"
                   :data-test-id="'fullscreen-blocks-icon-block-' + blockIndex"
-                  :src="block[0].value || '/content/images/fullscreenPlaceholderImage.png'"
+                  :src="block[0].value"
               >
               <p
                   class="cly-content-block-list-input__list-block-header-display-title"