Fix flaky AVB test from late verity_update_state

CtsNativeVerifiedBootTestCases is currently flaky due to race conditions
between verity_update_state and the test running.

Moving the call to verity_update_state before zygote-start should fix
the test.

Bug: 253033920
Test: Boot Android and check that partitions.system.verified.hash_alg
    has a non-empty value
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Change-Id: I9d252b0b6d74ed784ec2ffe091de2db53c5f45ba