Revert: Android perf tests: kill adbd on the device after running a test.

There's some data indicating that adbd on the device sometimes
spontaneously restores its connection.
After running a test, let's kill adbd and forwarder and wait for bit.

Reverts crrev.com/227038: this is not helping.

BUG=
NOTRY=True

Review URL: https://codereview.chromium.org/26186003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227278 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227278