MC-5054: User Can Bypass File Type Validation In PageBuilder's File Upload Spots

Add BackgroundImageInvalidMimeType MFTF test

Author: danmooney2

app/code/Magento/PageBuilder/Test/Mftf/Data/BackgroundFormData.xml

@@ -218,6 +218,16 @@
         <data key="extension">sql</data>
         <data key="errorMessage">We don't recognize or support this file extension type.</data>
     </entity>
+    <entity name="PageBuilderBackgroundImage_InvalidMimeType" type="pagebuilder_background_image_property">
+        <data key="name">Background Image</data>
+        <data key="section">background</data>
+        <data key="fieldName">background_image</data>
+        <data key="value">not-a.png</data>
+        <data key="fileName">not-a</data>
+        <data key="extension">png</data>
+        <data key="path">wysiwyg</data>
+        <data key="errorMessage">File validation failed.</data>
+    </entity>
     <!-- Background Mobile Image -->
     <entity name="PageBuilderBackgroundMobileImage_Default" type="pagebuilder_background_mobile_image_property">
         <data key="name">Background Image</data>

app/code/Magento/PageBuilder/Test/Mftf/Test/AdminPageBuilderBackgroundFormAttributeTests.xml

@@ -1148,6 +1148,26 @@
             <argument name="backgroundImage" value="PageBuilderBackgroundImage_JPG"/>
         </actionGroup>
     </test>
+    <test name="BackgroundImageInvalidMimeType" extends="BackgroundImageInvalidFileSize">
+        <annotations>
+            <features value="PageBuilder"/>
+            <stories value="Background Form"/>
+            <title value="Background Image - Invalid Mime Type"/>
+            <description value="Tests that the Background Image attribute functions as expected for files with correct extension but invalid mime type"/>
+            <severity value="CRITICAL"/>
+            <useCaseId value="MC-5054"/>
+            <testCaseId value="MC-5071"/>
+            <group value="pagebuilder"/>
+            <group value="pagebuilder-banner"/>
+            <group value="pagebuilder-backgroundForm"/>
+        </annotations>
+        <actionGroup ref="attachInvalidFileOnSlideOut" stepKey="attachInvalidFileOnSlideOut">
+            <argument name="property" value="PageBuilderBackgroundImage_InvalidMimeType"/>
+        </actionGroup>
+        <actionGroup ref="attachInvalidFileOnSlideOut" stepKey="attachInvalidFileOnSlideOut2">
+            <argument name="property" value="PageBuilderBackgroundImage_InvalidMimeType"/>
+        </actionGroup>
+    </test>
     <test name="BackgroundMobileImageJPG">
         <annotations>
             <features value="PageBuilder"/>