Final icons in dream overlay status bar.

This change adds the rest of the conditional icons to the dream overlay
status bar. All icons are currently hidden. A follow-up changes will
implement the logic to show them. Also, the battery icon has been
removed.

Test: atest DreamOverlayStatusBarViewControllerTest
Bug: 216831310
Change-Id: I2ba271102a3fc0c56d4214165d980b7f2c8ee055