Speed up odsign_e2e_tests.

This change moves preparation code and cleanup code to
@BeforeClassWithInfo and @AfterClassWithInfo respectively, which run
only once. It reduces the runtime of the test by ~85%. After the
change, the test only takes 5 minutes on Cuttlefish.

Note that any test state will NOT be reset after the change. Test cases
are ordered in a way that state changes won't cause problems.

Bug: 199114301
Test: atest odsign_e2e_tests
Change-Id: Ic5ba84a3a274322f5ba8fec3119419cd3c0ee1c4
1 file changed