Revert^2 "Update NetworkAgent#register to compatible with old NetworkAgentTest"

This reverts commit db884c9a93de747c96d0665ebbbf9af2047f862f.

Reason for revert: reason of aosp/2849874 revert is solved by aosp/2854408

Change-Id: Ic5ffddf2f811c0d2c359f292c3b44b833bae5eaa
2 files changed