Don't use getInitializedValue in GrantPermissionsViewModel

The grant permission buttons are SOMEHOW being clicked before the
packageInfo variable is initialized, despite the buttons being shown
being directly dependent on the packageInfo. Remove the usage of
getInitializedValue, and add a log if a button is clicked before the
packageInfo is ready.

Bug: 220052891
Test: presubmit
Change-Id: I08b27f47dd56fd9675d211a48ba4cff552041e31