migrate viewClass prop to class attribute

src/components/media_modal/media_modal.vue

 <template>
   <Modal
     v-if="showing"
-    view-class="media-modal-view"
+    class="media-modal-view"
     @close="hide"
   >
     <img

src/components/modal/modal.js

 const Modal = {
   props: {
-    viewClass: {
-      type: String
-    },
     isOpen: {
       type: Boolean,
       default: true

src/components/modal/modal.vue

@@ -2,7 +2,7 @@
   <div
     v-show="isOpen"
     v-body-scroll-lock="isOpen"
-    :class="['modal-view', viewClass]"
+    class="modal-view"
     @click.self="closeModal"
   >
     <slot />

src/components/post_status_modal/post_status_modal.vue

@@ -2,7 +2,7 @@
   <Modal
     v-if="isLoggedIn && !resettingForm"
     :is-open="modalActivated"
-    view-class="post-form-modal-view"
+    class="post-form-modal-view"
     @close="closeModal"
   >
     <div class="post-form-modal-panel panel">