Add test to ota_interface.JobInfo.

Add testcases for ota_interface.JobInfo, which is used as object to
store task information and serve/read data to/from database.
Refer to:
https://android-review.googlesource.com/c/platform/development/+/1736940
for more details.

Test: python test_ota_interface.py -v
Change-Id: I74dcb16390078bd9258da490e21cb2b73dd78e81
2 files changed