Use correct way of enabling blobs on dartk-bare-{simarm,simarm64}

Change-Id: Icce8bda1f186fe01f86514f697adc1f88fc500cd
Reviewed-on: https://dart-review.googlesource.com/c/89120
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: William Hesse <whesse@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
diff --git a/tools/bots/test_matrix.json b/tools/bots/test_matrix.json
index 3aebd98..44f3398 100644
--- a/tools/bots/test_matrix.json
+++ b/tools/bots/test_matrix.json
@@ -303,7 +303,8 @@
     }},
     "dartkp-bare-linux-(debug|release)-(simarm|simarm64)": {
       "options": {
-        "vm-options": ["--no-enable-malloc-hooks", "--use-bare-instructions", "--use-blobs"]
+        "vm-options": ["--no-enable-malloc-hooks", "--use-bare-instructions"],
+        "use-blobs": true
     }},
     "dartk-(linux|mac)-(debug|release)-(ia32|x64)": { },
     "dartk-checked-linux-release-x64": {