TBR: discovery/mojo: testing dart apptest failure

  - Try with a large timeout value

  https://github.com/vanadium/issues/issues/1278

Change-Id: Ia191525777c8ae1ac7fc919704980683b4556854
diff --git a/mojoapptests b/mojoapptests
index 362ef84..88c0b2f 100644
--- a/mojoapptests
+++ b/mojoapptests
@@ -8,13 +8,13 @@
     "shell-args": ["--args-for=https://mojo.v.io/discovery.mojo --use-mock"],
     "timeout": 120,
   },
-  # Disable dart apptests due to flakiness.
+  # Testing dart apptests timeout failure with a large timeout value.
   # See https://github.com/vanadium/issues/issues/1278
-  #
-  # {
-  #   "test": "https://dart.test.mojo.v.io/discovery_apptests.dart",
-  #   "type": "dart",
-  #   "dart_strict_mode": True,
-  #   "shell-args": ["--args-for=https://mojo.v.io/discovery.mojo --use-mock"],
-  # }
+  {
+    "test": "https://dart.test.mojo.v.io/discovery_apptests.dart",
+    "type": "dart",
+    "dart_strict_mode": True,
+    "shell-args": ["--args-for=https://mojo.v.io/discovery.mojo --use-mock"],
+    "timeout": 1200,
+  }
 ]