Backport of UI: Add check for renewal time before triggering renew-se…

…lf into release/1.8.x (#13956)

* backport of commit b699588

* backport of commit a27fcf3

Co-authored-by: hashishaw <cshaw@hashicorp.com>

changelog/13950.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+ui: trigger token renewal if inactive and half of TTL has passed
+```

ui/app/services/auth.js

@@ -291,9 +291,10 @@ export default Service.extend({
   },
 
   setLastFetch(timestamp) {
+    const now = this.now();
     this.set('lastFetch', timestamp);
-    // if expiration was allowed we want to go ahead and renew here
-    if (this.allowExpiration) {
+    // if expiration was allowed and we're over half the ttl we want to go ahead and renew here
+    if (this.allowExpiration && now >= this.renewAfterEpoch) {
       this.renew();
     }
     this.set('allowExpiration', false);