R1:4a6229ee693b

Remove some no-op "canUninstall()" Application methods

Summary: The default behavior of these methods is to return `true`, so these overrides have no effect.

Test Plan: `grep`; poked around.

Reviewers: chad

Reviewed By: chad

Subscribers: hach-que

Differential Revision: https://secure.phabricator.com/D16985