Add CTS tests for ApfCapabilities static APIs.

Add tests for getApfEtherTypeBlackList and getApfDrop8023Frames APIs.

Bug: 150640397
Test: atest CtsNetTestCasesLatestSdk:android.net.apf.ApfCapabilitiesTest
      on both of Q and R devices.

Change-Id: I11555934df4b27cbb6b7ddbb81022d8fb7c25e15
Merged-In: I11555934df4b27cbb6b7ddbb81022d8fb7c25e15
(cherry picked from commit 7d51a724)