Revert Headsup, there is an app for this now :)

This reverts commit 2bfc0cc8df6a1c98581c3dacaf3a5734fa27c946.

Revert "fixes for heads up"

This reverts commit 96e7406c313e3a24887a4ca1aa3e6c5f06ae8b60.

Revert "HeadsUp: Filter out notifications from system uid packages."

This reverts commit 213c8f36d992d7df5809186e6bd626b9264b4fd6.

Revert "HeadsUp: Fix resetHeadsUpDecayTimer."

This reverts commit 878d6bef4de1b837f264c8177219561de3f3a21b.

Revert "HeadsUp: Add heads up blacklist options. (1/2)"

This reverts commit 322ea52bbaa87ce2401fad88cae60aa64f7601de.

Revert "SystemUI: Expose heads up."

This reverts commit e940f7b545259b714a2b549d76f21e2badfdf958.