This commit:
- Adds test for remotely initiated rekey for IKE and Child SA
- Makes IkeTunUtils support building and injecting requests
- Adds method to parse hex to long because Long.parseLong cannot
handle negative long value
Bug: 155821007
Test: atest CtsIkeTestCases
Change-Id: I299cf190261ac15397f9ed389adb2c69e94a6507