Revert "Refactor onIpv6AddressRemoved callback in IpClient."

This reverts commit efdd91cfa7271cb73b96011fefee118d9d401450.

Reason for revert: <aosp/2846095 introduces CompareResults method to check if one IPv6 address has been removed, but that way also introduce the flakiness, revert this CL to fix the flaky tests first>

Change-Id: I56e41cfe005881b99da5fade90a27514bda5a7ce
3 files changed