[Sb] New status bar wifi and mobile icons

Based on the new_status_bar_icons flag, we optionally load a new style
of wifi and mobile icon.

Also, due to the new style of icon being dual-tone, this change modifies
our DarkIconDispatcherImpl and DualToneHandler classes to use 100% alpha
black instead of the currently-defined gray that is in the theme.

Test: manually by setting the flag
Bug: 314812750
Flag: ACONFIG com.android.settingslib.flags.new_status_bar_icons DEVELOPMENT
Change-Id: I915227d597da4ffca0fd007e097abafca6741246