Change plans prop to plan

ee/app/assets/javascripts/subscriptions/buy_minutes/components/app.vue

@@ -23,7 +23,6 @@ export default {
   emptySvg,
   data() {
     return {
-      plans: null,
       hasError: false,
     };
   },
@@ -59,10 +58,10 @@ export default {
   />
   <step-order-app v-else-if="!$apollo.loading">
     <template #checkout>
-      <checkout :plans="plans" />
+      <checkout :plan="plans[0]" />
     </template>
     <template #order-summary>
-      <order-summary :plans="plans" />
+      <order-summary :plan="plans[0]" />
     </template>
   </step-order-app>
 </template>

ee/app/assets/javascripts/subscriptions/buy_minutes/components/checkout.vue

@@ -8,8 +8,8 @@ import PaymentMethod from './checkout/payment_method.vue';
 export default {
   components: { AddonPurchaseDetails, BillingAddress, PaymentMethod, ConfirmOrder },
   props: {
-    plans: {
-      type: Array,
+    plan: {
+      type: Object,
       required: true,
     },
   },
@@ -22,7 +22,7 @@ export default {
   <div class="checkout gl-display-flex gl-flex-direction-column gl-align-items-center">
     <div class="flash-container"></div>
     <h2 class="gl-mt-6 gl-mb-7 gl-mb-lg-5">{{ $options.i18n.checkout }}</h2>
-    <addon-purchase-details :plans="plans" />
+    <addon-purchase-details :plan="plan" />
     <billing-address />
     <payment-method />
     <confirm-order />