Reapply "Always disconnect agents immediately."

Now that the faulty test is fixed,
This reverts commit 19dcc447c47b732bc2a3f0802097031accaa8ecb.

Test: ConnectivityCoverageTests CtsNetTestCases FrameworksTelephonyTests
Change-Id: I30fa35cef1729e6ecd4140c52fabfa2da1a9bb4b
3 files changed