Disable AppListServiceMacInteractiveTest.ShowAppListUsingShim

Mac10.6 Tests (1) interactive_ui_tests
AppListServiceMacInteractiveTest.ShowAppListUsingShim is flaky.

http://build.chromium.org/p/chromium.mac/builders/Mac10.6%20Tests%20%281%29/builds/48525
http://build.chromium.org/p/chromium.mac/builders/Mac10.6%20Tests%20%281%29/builds/48527
http://build.chromium.org/p/chromium.mac/builders/Mac10.6%20Tests%20%281%29/builds/48529

interactive_ui_tests AppListServiceMacInteractiveTest.ShowAppListUsingShim
failed in these three builds, but not in the builds in between. Looks flaky.

A recent relevant change is r245472.

TBR=tapted
BUG=335550


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245517 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245517