Test remotely initiated rekey

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
4 files changed
tree: 757178685412414026fb7d0741c64a565cc9aa50
  1. tests/