RFR: 8266860: [macos] Incorrect duration reported for HLS live streams

[Alexander Matveev]

For indefinite durations CMTimeGetSeconds was returning NaN (not-a-number double value) and our code expects -1.0. Based on doc we should be using CMTIME_IS_INDEFINITE to test if duration is indefinite. Fixed by using CMTIME_IS_INDEFINITE to test if duration is indefinite and if true -1.0 will be return to our Java layer.

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Commit messages:
 - 8266860: [macos] Incorrect duration reported for HLS live streams

Changes: https://git.openjdk.java.net/jfx/pull/495/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=495&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8266860
  Stats: 5 lines in 1 file changed: 3 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jfx/pull/495.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/495/head:pull/495

PR: https://git.openjdk.java.net/jfx/pull/495