Add an developer option to enable config_navBarDefaultTransparent

This enables the user to make navigation bar color transparent by
default. It will only affect apps which don't specify the navigation
bar color.

Fix: 232195501
Test: atest TransparentNavigationBarPreferenceControllerTest
Change-Id: I91581558b92abeaa3501b9749f1a1ab43db8e771
4 files changed