Added GET_BACKGROUND_INSTALLED_PACKAGES to SYSTEM_APP_PROTECTION_SERVICE role.

As discussed with zhanghai@ we will add the permission to the role and
handle manifest-flagging if needed when it lands.

For more info: go/bic-v

Test: m
Bug: 296060433
Change-Id: I25c0f10c23fb02c3f7db7273ab9bd5fa1a0c618e