Update exception thrown for consistency.

The PackageManagerInternal APIs for checking if the app is in a stopped
state or is quarantined throw an IllegalArgumentException when the
package is not found - however, this was not documented anywhere.

Instead, to be consistent with other PackageManager APIs, start throwing
a NameNotFoundException from the internal APIs and ensure the new
exception is caught from the public APIs and rethrown as
IllegalArgumentException.

This change updates the documentation as well, fixes a typo in a method
name, and also updates the logging level for when these exceptions occur.

Bug: 314863695
Test: builds/flashes/boots (mostly documentation changes)
Change-Id: Ia7b30ce4e16b5e40bd767cd15dbf2cd2728567dd