Make LinkPropertiesTest compatible with Q

CompareResult had been moved from LinkProperties to LinkPropertiesUtils
so this change ignores testCompareResult() on Q and only check
compareAllRoutes() works while android version is at least R.

Bug: 151782584
Test: atest CtsNetTestCasesLatestSdk:LinkPropertiesTest
Change-Id: I38b0d83abf983b3bcc01fc6aea2e5cc307734198