Revert "Active display: Add threshold to proximity sensor…"

Hopefully solves the error with screen off when proximity is covered inadvertently

This reverts commit 90f8ccc2b69f0eb584593bf8be677d85bb1f2dcd.

Conflicts:

	packages/SystemUI/src/com/android/systemui/statusbar/policy/activedisplay/ActiveDisplayView.java

Change-Id: Ie63e873be8ab37c8602b65eb5dd807aa102cd1dd