Support 64-bit certificate times

The KeyMint VTS tests send some 64-bit before/after
time values. Switch from time_t to int64_t to fix
test breakage on 32-bit Trusty builds.

Bug: 334992641
Test: qemu-generic-arm64u32-test-debug: \
    VtsAidlKeyMintTargetTest \
    --gtest_filter="*WithSpecified*"
Change-Id: I6e7c3e13102d3720394f595cba3630aae976e2de
1 file changed