RFR: 8351757: Test java/foreign/TestDeadlock.java#FileChannel_map timed out after passing

[Per Minborg]

This PR proposes to increase the timeout values for two tests.

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Commit messages:
 - Increase timeouts

Changes: https://git.openjdk.org/jdk/pull/24511/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24511&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351757
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/24511.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24511/head:pull/24511

PR: https://git.openjdk.org/jdk/pull/24511