Scope package manager queries for ephemeral apps

Ephemeral apps can only see their own components or those components
exposed via the "visibleToEphemeral" XML attribute.

Normal apps can only see other normal apps. There is no way to expose
ephemeral components to normal apps.

Bug: 33458220
Test: Manually install ephemeral/normal apps and ensure they can only see appropriate components
Change-Id: I6ae65fd2a6ddc9aa9691f02cd55d4953048966b0