cros: Allow ash to launch accessibility_autoclick under mash

The "accessibility_autoclick" service is a small mojo app that
implements the "automatically click when the mouse stops moving"
feature for users with difficulty clicking the mouse. It was
missing from ash's manifest file.

This fixes browser_tests AccessibilityFeatureaApiTest and
ChromeOSInfoPrivateTest.TestGetAndSet under mash.

Bug: 678687, 805713
Test: browser_tests --mash
Change-Id: I3611b80209809247a64987d339cc513e1caeee06
Reviewed-on: https://chromium-review.googlesource.com/889524
Commit-Queue: James Cook <jamescook@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532504}

ash/manifest.json

@@ -47,6 +47,7 @@
       },
       "requires": {
         "*": [ "accessibility", "app" ],
+        "accessibility_autoclick": [ "mash:launchable" ],
         "ash_pref_connector": [ "pref_connector" ],
         "catalog": [ "directory" ],
         "local_state": [ "pref_client" ],

testing/buildbot/filters/mojo.fyi.mash.browser_tests.filter

@@ -13,9 +13,7 @@
 
 # ChromeVoxPanel directly calls into ash to set panel height.
 # http://crbug.com/628655
--AccessibilityFeatureaApiTestInstantiatePermission/AccessibilityFeaturesApiTest.Set*
 -AccessibilityManagerTest.*
--ChromeOSInfoPrivateTest.TestGetAndSet
 -PolicyTest.ScreenMagnifierTypeFull
 -PolicyTest.ScreenMagnifierTypeNone
 -PolicyTest.UnifiedDesktopEnabledByDefault