Fix typo in run-jdwp-tests.sh

jdpa -> jpda.

Test: ./art/tools/run-jdwp-tests.sh \
            --mode=host \
            --debug \
            --variant=x64 \
            -Xplugin:$ANDROID_HOST_OUT/lib64/libopenjdkjvmtid.so \
            --jdwp-path /usr/lib/jvm/default-java/jre/lib/amd64/libjdwp.so

Change-Id: I3d7743faeee0b152188d4d5d3d482e130f55e6d1