Refactor the code to check the metadata

The two functions check_wipe_package() and check_newer_ab_build() were
using the same flow; and checked the same device properties against the
metadata file in the package. These properties include: ota_type,
pre-device, and serial number.

Therefore, we can consolidate the checks to a single function; and
continue to check the fingerprint and timestamp only for AB updates.

This change also addresses the need to accept multiple serial number in
the wipe package.

Bug: 118401208
Test: unit tests pass
Change-Id: Ia6bc48fb6effcae059a2ff2cf71764b4136b4c00