Fix testDataMigrationUtils fail on R device

Since the test is using JUnit3, which doesn't support rules
or assumeTrue, the IgnoreUpTo rule does not take effect.
Replace with a return statement as short term solution to
unblock presumit.

Test: atest CtsNetTestCasesLatestSdk:android.net.cts.NetworkStatsManagerTest
      on R device
Bug: 219099881
  (cherry-picked from ag/16927063)
Change-Id: I6056da19324715237c6fdac0975fb89de8a04416
Merged-In: I6056da19324715237c6fdac0975fb89de8a04416
1 file changed