Various layout fixes for app install dialog

dashboard/src/components/AppInstallDialog.vue

@@ -154,7 +154,7 @@ defineExpose({
 <template>
   <Dialog ref="dialogHandle" @close="onClose()">
     <div class="content" :class="{ 'step-detail': step === STEP.DETAILS, 'step-install': step === STEP.INSTALL }">
-      <div class="header">
+      <div class="app-install-header">
         <div class="summary">
           <div class="title">{{ manifest.title }}</div>
           <div class="lastUpdated">{{ $t('appstore.installDialog.lastUpdated', { date: prettyDate(app.creationDate) }) }}</div>
@@ -228,11 +228,10 @@ defineExpose({
   width: 480px;
 }
 
-.header {
+.app-install-header {
   display: flex;
   align-items: center;
   justify-content: space-between;
-  margin: 4px;
 }
 
 .summary {