RFR: 1604: Unify behavior in gradlew and gradlew.bat

[Erik Joelsson]

This patch changes the gradlew.bat script to download and extract Gradle and the JDK in the same locations as the gradlew bash script, so that running either script interchangeably works fine in the same workspace.

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Commit messages:
 - SKARA-1604

Changes: https://git.openjdk.org/skara/pull/1377/files
 Webrev: https://webrevs.openjdk.org/?repo=skara&pr=1377&range=00
  Issue: https://bugs.openjdk.org/browse/SKARA-1604
  Stats: 15 lines in 1 file changed: 3 ins; 4 del; 8 mod
  Patch: https://git.openjdk.org/skara/pull/1377.diff
  Fetch: git fetch https://git.openjdk.org/skara pull/1377/head:pull/1377

PR: https://git.openjdk.org/skara/pull/1377