Make Transforms Unidirectional

Convert the IpSecTransform from being a bi-directional
pair of SAs to a unidirectional single SA. This CL
also removes the concept of "direction from SAs meaning
that a IpSecTransform may now be applied to a socket
in either direction.

-Remove direction parameter from SAs and SPIs.
-Convert to using source and destination rather than
 local and remote addresses.

Bug: 71717213
Test: CTS - IpSecManagerTest
Change-Id: I7150c2b03057e18a7d9d3edff302baf10e1ee729
6 files changed