android: Report error if CHILD_SA rekeying fails
android: Reestablish IKE_SA if CHILD_SA rekeying failed
proposal: Fix equals()
child-cfg: Ignore duplicate proposals

If ESP proposals are added once with and once without DH groups
duplicates result during IKE_AUTH when DH groups are stripped.
android: Add DH groups to ESP proposals
android: Reduce CHILD_SA lifetime
Merge branch 'android-pfs'

Changes how CHILD_SA rekeying errors are handled in the Android app and adds
CHILD_SA proposals with DH groups.