Expose MD4Digest for EAP MSCHAPv2.

MD4 is required by EAP MSCHAPv2 for peer authentication to an
authentication server. This commit exposes the BouncyCastle MD4Digest
implementation.

Bug: 140928282
Test: Build succeeds. EAP using this, tests passing.
Change-Id: I17fc63e3bc4086317b58be2dd51eed4733c163c4
1 file changed