Build the Flutter engine for android_debug and then the dist target

scripts/slave/recipes/flutter/engine.expected/linux.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport os, sys\nfrom common import chromium_utils # Error? See https://crbug.com/584783.\n\npath = sys.argv[1]\nif os.path.exists(path):\n  for p in (os.path.join(path, x) for x in os.listdir(path)):\n    if os.path.isdir(p):\n      chromium_utils.RemoveDirectory(p)\n    else:\n      os.unlink(p)\n",
       "[SLAVE_BUILD]"
     ],
     "name": "rmcontents everything",
     "~followup_annotations": [
@@ skipping 217 matching lines @@
     ],
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/dart-sdk/dart-sdk/bin:%(PATH)s"
     },
     "name": "gn --android"
   },
   {
     "cmd": [
       "ninja",
       "-C",
+      "[SLAVE_BUILD]/src/out/android_debug"
+    ],
+    "env": {
+      "PATH": "[SLAVE_BUILD]/src/third_party/dart-sdk/dart-sdk/bin:%(PATH)s"
+    },
+    "name": "build android_debug"
+  },
+  {
+    "cmd": [
+      "ninja",
+      "-C",
       "[SLAVE_BUILD]/src/out/android_debug",
       ":dist"
     ],
     "env": {
       "PATH": "[SLAVE_BUILD]/src/third_party/dart-sdk/dart-sdk/bin:%(PATH)s"
     },
     "name": "build android_debug :dist"
   },
   {
     "cmd": [
@@ skipping 838 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@  chromium_utils.RemoveDirectory(sys.argv[1])@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]