RFR: 8260554: Missing copyright headers on some Lanai files

[Kevin Rushforth]

1. Add missing copyright headers
2. Revert changes to files that only differ from jdk/master in copyright years or whitespace changes
3. Update copyright years to 2021

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Commit messages:
 - 8260554: Missing copyright headers on some Lanai files
 - 8260554: Missing copyright headers on some Lanai files
 - 8260554: Missing copyright headers on some Lanai files

Changes: https://git.openjdk.java.net/lanai/pull/160/files
 Webrev: https://webrevs.openjdk.java.net/?repo=lanai&pr=160&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8260554
  Stats: 454 lines in 83 files changed: 375 ins; 2 del; 77 mod
  Patch: https://git.openjdk.java.net/lanai/pull/160.diff
  Fetch: git fetch https://git.openjdk.java.net/lanai pull/160/head:pull/160

PR: https://git.openjdk.java.net/lanai/pull/160