Use new manifest flag to gate clearing data during restore

Use the new manifest flag introduced in ag/5762489 to gate clearing data
during restore.

Bug: 120267643
Test: 1) atest RunBackupFrameworksServicesRoboTests
      2) atest CtsBackupTestCases
      3) atest CtsBackupHostTestCases
      4) atest GtsBackupTestCases
      5) atest GtsBackupHostTestCases

Change-Id: Ida4a9e96f44d1c740d217faed2b9f928e02865ec