Add feature flag for IPSEC_TUNNEL_MIGRATION to Pixel6/7/8

This commit adds the IPSEC_TUNNEL_MIGRATION feature flag,
with XFRM_MIGRATE used as the implementation

Verified on bluejay

Bug: 273379472
Test: build, flash and verify with "adb shell pm list features"
Test: atest IpSecManagerTunnelTest
Change-Id: Ia19663288b389dbfa0ce5ca328b5706b1767db78
1 file changed