NavigationBar: Custom height (1/2)

Ported from: http://review.cyanogenmod.org/#/c/29636/

Change-Id: I007776c251dc26965b2d93d1d390324e561e5da9

Conflicts:
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
Clean up navigation bar height & fix it

Change-Id: I03e6edf14014f8293bd82f6f313454ce4cd56139

Conflicts:
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java