revert: perf(ngAnimate): listen for document visibility changes

This reverts commit b377d6b043db9c8da4e68493892f75a0f9759464.

This commit introduces dependency on $document during the injector
bootstrap. This is usually fine, except for cases when $document is
mocked out in existing test suites. Since we don't provide an out
of box mock, people have created their owns that don't sufficiently
mock all apis. In these environments this change results in errors
like $document.on is not a function, etc.