[jdk17u-dev] RFR: 8353662: Add test for non-local file URL fallback to FTP

[Goetz Lindenmaier]

I backport this for parity with 17.0.17-oracle.

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Commit messages:
 - Backport cae7a206a2f4b47d6757408d62b88be060113ad5

Changes: https://git.openjdk.org/jdk17u-dev/pull/3740/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3740&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353662
  Stats: 145 lines in 1 file changed: 145 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3740.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3740/head:pull/3740

PR: https://git.openjdk.org/jdk17u-dev/pull/3740