mandoline filesystem: add a sqlite3 vfs to proxy filesystem usage.

mojo/tools/data/apptests

 # This file contains a list of Mojo gtest unit tests.
 #
 # This must be valid Python. It may use the |config| global that will be a
 # mopy.config.Config object, and must set a |tests| global that will contain the
 # list of tests to run.
 #
 # The entries in |tests| are dictionaries of the following form:
 #   {
 #     # Required URL for apptest.
 #     "test": "mojo:test_app_url",
@@ skipping 37 matching lines @@
     {
       "test": "mojo:filesystem_apptests",
       "type": "gtest_isolated",
     },
     {
       "test": "mojo:html_viewer_apptests",
       "type": "gtest_isolated",
       "args": ["--is-headless"]
     },
     {
+      "test": "mojo:mandoline_frame_apptests",
+      "type": "gtest_isolated",
+      "args": ["--use-headless-config"]
+    },
+    {
       "test": "mojo:resource_provider_apptests",
       "type": "gtest_isolated",
     },
     {
-      "test": "mojo:mandoline_frame_apptests",
+      "test": "mojo:sql_apptests",
       "type": "gtest_isolated",
-      "args": ["--use-headless-config"]
     },
   ]