Disable E2E tests on SF build

We'll be changing how the E2E tests are run on TeamCity: instead of
running them via ant on the Linux build agent, we'll be running them in
a Windows build agent after the Linux build agent completes its work.
The first step is to make sure that the Linux build agent does NOT run
the actual tests (but we still want to run installForE2ETest because
that sets up the Apache server that will be used by the Windows build
agent when it runs the actual E2E tests).

Note that we're disabling this step by renaming it, rather than by
commenting it out, because XML comments cannot contain the "--" string
(as the long-form options use).