Add a proposal for improving app routability during cell presence loss

[cfdreddbot]

Hey jvshahid!

Thanks for submitting this pull request! I'm here to inform the recipients of the pull request that you and the commit authors have already signed the CLA.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/157947458

The labels on this github issue will be updated when the story is started.