Add wrapper method from settings app's wrapper.

- there are two different version of PackageManagerWrapper in settings.
Removing the one in Settings app, and consolidate all wrapper methods
in here.
- move PackageManagerWrapper to the new wrapper package.
- change PackageManagerWrapper to a class instead of interface/impl.

Bug: 65634579
Test: make RunSettingsLibRoboTests
Change-Id: Ibf61480eeb8e1554071c71eeae53a1bf3a15074f