Add skeleton SyncTest for NDK libsync

There's no actual test code yet, but this is enough to confirm that
the NDK libsync.so symbols are incorrect, and to verify the fix.
Actual tests are being written and will come in a followon change.

Bug: 62229958
Test: bit CtsGraphicsTestCases:android.graphics.cts.SyncTest
Change-Id: I71dc9accebfeb95d332f514dae6c0c07a194c4ae
3 files changed