Expand home notification height

The home notification static height of 116px is too cramped for longer
messages, such as the one used for the Sai migration. The old height is
now used for the minimum height instead, with a margin to ensure the
text doesn't get too close to the buttons.

ui/app/components/app/home-notification/index.scss

@@ -8,7 +8,7 @@
   background: rgba(36, 41, 46, 0.9);
   box-shadow: 0 2px 10px rgba(0, 0, 0, 0.12);
   border-radius: 8px;
-  height: 116px;
+  min-height: 116px;
   padding: 16px;
 
   @media screen and (min-width: 576px) {
@@ -95,6 +95,7 @@
   &__buttons {
     display: flex;
     width: 100%;
+    margin-top: 10px;
     justify-content: flex-start;
     flex-direction: row-reverse;
   }