Don't patch build path to DEX jar in dex_preopt_config_merger.py.

The initial path value is correct, there's no need to patch it.

Bug: 132357300
Test: lunch aosp_cf_x86_64_phone-userdebug && m && launch_cvd \
        adb wait-for-device && adb root && adb logcat \
        | grep -E 'ClassLoaderContext [a-z ]+ mismatch'
        # empty grep output, no errors
Change-Id: Iaa9171e7db348ad469ec56b977b5f2226f353284