Fix testUsesSdk test to use higher extension version.

The installation of sdk extension version that does not exist should
fail. Since extension 5 exist now, the test started failing.
This CL changes the non-existent extension version to a higher value to
ensure it does not exist, to ensure installation failure in the test.

Bug: 257466496
Test: atest FrameworksServicesTests:com.android.server.pm.parsing.PackageParserLegacyCoreTest#testUsesSdk

Change-Id: I5fb3ceed2b6db3dd5a5154df941918b97cb52204