Revert "Enable/disable navigation bar on the fly, without reboot (Confirmed working)"

This implementation is better to me: https://github.com/AOSPA-legacy/android_frameworks_base/commit/b5b9eb04a06e5c19bd4291d842ac394494bfaff7

This reverts commit 12c9678da3d79f316f09f427b4293fdbdb46e7ee.

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java