Use `PushFilePreparer` to push files in dex-builder-test

This change modifies the test config file by switching to use `PushFilePreparer` instead of `FilePusher`, since the `FilePusher` class which is defined in `compatibility-tradefed` is designed for the tests that are part of compatibility suite, but dex-builder-test is not.

Bug: 220991354
Test: atest-src dex-builder-test \
          --experimental-device-driven-test \
          --experimental-java-runtime-dependencies \
          --bazel-arg=--test_timeout=48000
Test: atest dex-builder-test
Change-Id: I85be14a454acac23705131c3a121c70fde07a138