Fix responsive in my channel/my videos pages

client/src/app/+my-account/my-account-video-channels/my-account-video-channels.component.scss

@@ -56,11 +56,19 @@
 }
 
 @media screen and (max-width: 800px) {
+  .video-channels-header {
+    text-align: center;
+  }
+
   .video-channel {
     flex-direction: column;
     height: auto;
     text-align: center;
 
+    .video-channel-names {
+      justify-content: center;
+    }
+
     img {
       margin-right: 0;
     }

client/src/app/+my-account/my-account-videos/my-account-videos.component.scss

@@ -100,6 +100,10 @@
     height: auto;
     text-align: center;
 
+    .video-info-name {
+      margin: auto;
+    }
+
     input[type=checkbox] {
       display: none;
     }

client/src/sass/include/_mixins.scss

@@ -411,9 +411,11 @@
   @include orange-button;
 
   .icon.icon-add {
-    @include icon(22px);
+    @include icon(20px);
 
-    margin-right: 3px;
+    position: relative;
+    top: -1px;
+    margin-right: 5px;
     background-image: url($imageUrl);
   }
 }