infra: Add fuchsia-angle-rel bot

Add a new FYI bot for Fuchsia that builds with angle_top_of_tree.

Bug: angleproject:3146

Change-Id: I993faf11739c6074c60b8dc7613489110fb15d40
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1610748Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Michael Spang <spang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659311}

infra/config/cr-buildbucket.cfg

@@ -3737,6 +3737,7 @@ buckets {
       name: "gpu-manual-try-linux-nvidia-tsn"
     }
     builders { mixins: "linux-try" name: "leak_detection_linux" }
+    builders { mixins: "linux-angle-try" name: "fuchsia-angle-rel" }
     builders { mixins: "linux-angle-try" name: "linux-angle-rel" }
     builders { mixins: "linux-angle-try" name: "linux_angle_deqp_rel_ng" }
     builders { mixins: "linux-angle-try" name: "linux_angle_ozone_rel_ng" }

infra/config/luci-milo.cfg

@@ -4347,6 +4347,9 @@ consoles {
   builders {
     name: "buildbucket/luci.chromium.try/android_angle_vk64_rel_ng"
   }
+  builders {
+    name: "buildbucket/luci.chromium.try/fuchsia-angle-rel"
+  }
   builders {
     name: "buildbucket/luci.chromium.try/linux-angle-rel"
   }
@@ -4462,6 +4465,9 @@ consoles {
   builders {
     name: "buildbucket/luci.chromium.try/fuchsia"
   }
+  builders {
+    name: "buildbucket/luci.chromium.try/fuchsia-angle-rel"
+  }
   builders {
     name: "buildbucket/luci.chromium.try/gpu-manual-try-android-l-nexus-5-32"
   }

tools/mb/mb_config.pyl

@@ -683,6 +683,7 @@
       'android_angle_deqp_rel_ng': 'deqp_android_release_trybot_arm64',
       'android_angle_vk32_deqp_rel_ng': 'deqp_android_vulkan_release_trybot',
       'android_angle_vk64_deqp_rel_ng': 'deqp_android_vulkan_release_trybot_arm64',
+      'fuchsia-angle-rel': 'gpu_fyi_tests_release_trybot',
       'linux-angle-rel': 'gpu_fyi_tests_release_trybot',
       'linux_angle_ozone_rel_ng': 'gpu_fyi_tests_ozone_linux_system_gbm_libdrm_release_trybot',
       'linux_angle_deqp_rel_ng': 'deqp_release_trybot',