Add GET_BACKGROUND_INSTALLED_PACKAGES permission and added to

com.android.shell for testing and BTS adb shell API.

New permission enables BICS to provide caller with all silently
installed apps for all users on a device without needing caller to be
granted overly permissive access.

For more info: go/bic-v

Bug: 296060433
Test: m
Change-Id: I3c3f9d9dc1d746fedc27bbb6e500f19bae9e72e2