Tweak milo config for chromium.linux xenial bot.

Bug: 812051
Change-Id: I32375672b2fef31603c2eefdd13fd60a12a40206
Reviewed-on: https://chromium-review.googlesource.com/1050435Reviewed-by: Ryan Tseng <hinoka@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556852}

infra/config/global/luci-milo.cfg

@@ -404,6 +404,11 @@ consoles: {
     category: "chromium.linux|release"
     short_name: "gcc"
   }
+  builders {
+    name: "buildbucket/luci.chromium.ci/linux-xenial-rel"
+    category: "chromium.linux|release"
+    short_name: "xen"
+  }
   builders: {
     name: "buildbucket/luci.chromium.ci/Linux Builder (dbg)(32)"
     category: "chromium.linux|debug|builder"
@@ -474,11 +479,6 @@ consoles: {
     category: "chromium.linux|ozone"
     short_name: "bld"
   }
-  builders {
-    name: "buildbucket/luci.chromium.ci/linux-xenial-rel"
-    category: "chromium.linux|xenial"
-    short_name: "rel"
-  }
 
   builders: {
     name: "buildbot/chromium.chromiumos/Linux ChromiumOS Full"
@@ -875,21 +875,26 @@ consoles: {
     category: "release"
     short_name: "bld"
   }
+  builders: {
+    name: "buildbucket/luci.chromium.ci/Linux Tests"
+    category: "release"
+    short_name: "tst"
+  }
   builders: {
     name: "buildbucket/luci.chromium.ci/linux-gcc-rel"
     category: "release"
     short_name: "gcc"
   }
+  builders {
+    name: "buildbucket/luci.chromium.ci/linux-xenial-rel"
+    category: "release"
+    short_name: "xen"
+  }
   builders: {
     name: "buildbucket/luci.chromium.ci/linux-jumbo-rel"
     category: "jumbo"
     short_name: "jumbo"
   }
-  builders: {
-    name: "buildbucket/luci.chromium.ci/Linux Tests"
-    category: "release"
-    short_name: "tst"
-  }
   builders: {
     name: "buildbucket/luci.chromium.ci/Linux Builder (dbg)(32)"
     category: "debug|builder"
@@ -953,11 +958,6 @@ consoles: {
     category: "ozone"
     short_name: "bld"
   }
-  builders {
-    name: "buildbucket/luci.chromium.ci/linux-xenial-rel"
-    category: "chromium.linux|xenial"
-    short_name: "rel"
-  }
 }
 
 consoles: {
@@ -2470,10 +2470,6 @@ consoles: {
     name: "buildbot/chromium.fyi/VR Linux"
     category: "linux"
   }
-  builders: {
-    name: "buildbot/chromium.fyi/Linux Xenial"
-    category: "linux"
-  }
   builders: {
     name: "buildbot/chromium.fyi/Mojo Android"
     category: "mojo"