Rewrite tests to use simplified plugin bootstrap

This reduced the tests execution time from 60 seconds to 8 seconds.
So now we can classify the size as small. Moreover, we don't need
to build and deploy the plugin during test execution and thus the
test can be run hermetically, so that we can remove local tag.

Change-Id: Ibe51dee4fd6185ad04a0cf3b5395a7e95f154e0a