[2/n] Add policy to skip the BlockedAppStreamingActivity

Along with the new onActivityLaunchBlocked callback, the VD owner
can have a custom experience on the VD when a launch is blocked or
when the launch falls back to the default display.

Flag: android.companion.virtualdevice.flags.activity_control_api
Test: presubmit and CTS
Bug: 333443509
Change-Id: I0327b7e317e15b47a95ff7751bf9338916298b95