Remove SocketUtils from incompatibilities

SocketUtils was moved to framework-connectivity in change:
I21c42f032efa6c10e36c749df3183ce9679303a7, but eventually moved back in
change I7028d334975f7536c06afac7a22200c33db707ac. That last change
missed reverting the changes in incompatibilities.txt and the prebuilt
API 30 definition.
Update the two files to revert references to SocketUtils.

Bug: 184299386
Test: m
Change-Id: I1611465ad5ad3d52e601f3b369a9f2b2810144a6
2 files changed