Adjust tests for renaming groupHint to cluster.

Bug: 146460486
Test: atest android.net.IpMemoryStoreTest
Test: atest com.android.server.connectivity.ipmemorystore.IpMemoryStoreServiceTest
Change-Id: Ia9797bb93aa4ff89147a77823d342dc22aec6a25
Merged-In: I69f7a2971cc5985d0f0078aecc39d4d6a6130033
(cherry-picked from aosp/1311654)
2 files changed