Add plain mode for the quick viewer.

When EXTRA_QUICK_VIEW_PLAIN is passed, then plain UI should be shown.
This is just a hint for third party apps, whic may ignore it.

Test: Not testable, as it's just a hint.
Bug: 32161075
Change-Id: Ie244d28d552f6c654be93a5749ac164d2a77d25f
4 files changed