Fix certificate notBefore and notAfter

Correct handling of negative date/times (dates before the epoch).

Ignore-AOSP-First: No merge path from AOSP
Bug: 177729159
Test: atest CtsKeystoreTestCases
Merged-In: I2f774a8759f120f273da811b28e95187bcf2f501
Change-Id: I2f774a8759f120f273da811b28e95187bcf2f501
3 files changed