Fix NPE for where intent.package is null but targetpkg is not.

- Also update WorkspaceItemProcessorTest with a new test and to use real intent instead of mock

Bug: 330250727
Test: unit tests
Flag: N/A
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:ce255ff6fdf4688afd5318dc3027f03691c85bc4)
Merged-In: I77e17901f4754c301ca20b3c6f93bbe29bead59b
Change-Id: I77e17901f4754c301ca20b3c6f93bbe29bead59b