RFR: 8247360: Add missing license file for Microsoft DirectShow Samples

[Kevin Rushforth]

This adds a missing third-party license file for the Microsoft DirectShow Samples.

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Commit messages:
 - 8247360: Add missing license file for Microsoft DirectShow Samples

Changes: https://git.openjdk.java.net/jfx/pull/252/files
 Webrev: https://webrevs.openjdk.java.net/jfx/252/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8247360
  Stats: 26 lines in 1 file changed: 26 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/252.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/252/head:pull/252

PR: https://git.openjdk.java.net/jfx/pull/252