Increase the frontend service idle timeout from 10 to 30 minutes

This should help reduce the occurrence of requests taking a long time
to process because a new instance is being spun up. We might consider
increasing this further to 60 minutes in the future if necessary.

This also increases the number of frontend instances on production to 8
from 6, since it appears like the issue we were attempting to mitigate
with that change is now fixed.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=173440059

java/google/registry/env/alpha/default/WEB-INF/appengine-web.xml

@@ -10,7 +10,7 @@
   <instance-class>B4</instance-class>
   <basic-scaling>
     <max-instances>4</max-instances>
-    <idle-timeout>10m</idle-timeout>
+    <idle-timeout>30m</idle-timeout>
   </basic-scaling>
 
   <system-properties>

java/google/registry/env/crash/default/WEB-INF/appengine-web.xml

@@ -10,7 +10,7 @@
   <instance-class>B4_1G</instance-class>
   <basic-scaling>
     <max-instances>10</max-instances>
-    <idle-timeout>10m</idle-timeout>
+    <idle-timeout>30m</idle-timeout>
   </basic-scaling>
 
   <system-properties>

java/google/registry/env/production/default/WEB-INF/appengine-web.xml

@@ -9,8 +9,8 @@
   <sessions-enabled>true</sessions-enabled>
   <instance-class>B4_1G</instance-class>
   <basic-scaling>
-    <max-instances>6</max-instances>
-    <idle-timeout>10m</idle-timeout>
+    <max-instances>8</max-instances>
+    <idle-timeout>30m</idle-timeout>
   </basic-scaling>
 
   <system-properties>

java/google/registry/env/sandbox/default/WEB-INF/appengine-web.xml

@@ -10,7 +10,7 @@
   <instance-class>B4</instance-class>
   <basic-scaling>
     <max-instances>4</max-instances>
-    <idle-timeout>10m</idle-timeout>
+    <idle-timeout>30m</idle-timeout>
   </basic-scaling>
 
   <system-properties>