Update license header

[joshuali925]

Description

#175

Issues Resolved

#175

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov-commenter]

Codecov Report

Merging #282 (3125416) into main (65f449b) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##               main     #282   +/-   ##
=========================================
  Coverage     99.90%   99.90%           
  Complexity     2687     2687           
=========================================
  Files           256      256           
  Lines          6524     6524           
  Branches        420      420           
=========================================
  Hits           6518     6518           
  Misses            5        5           
  Partials          1        1           

Impacted Files	Coverage Δ
...a/org/opensearch/sql/analysis/AnalysisContext.java	100.00% <ø> (ø)
...ain/java/org/opensearch/sql/analysis/Analyzer.java	100.00% <ø> (ø)
...rg/opensearch/sql/analysis/ExpressionAnalyzer.java	100.00% <ø> (ø)
...rch/sql/analysis/ExpressionReferenceOptimizer.java	100.00% <ø> (ø)
...ensearch/sql/analysis/NamedExpressionAnalyzer.java	100.00% <ø> (ø)
...org/opensearch/sql/analysis/QualifierAnalyzer.java	100.00% <ø> (ø)
...nsearch/sql/analysis/SelectExpressionAnalyzer.java	100.00% <ø> (ø)
...a/org/opensearch/sql/analysis/TypeEnvironment.java	100.00% <ø> (ø)
...nsearch/sql/analysis/WindowExpressionAnalyzer.java	100.00% <ø> (ø)
.../org/opensearch/sql/analysis/symbol/Namespace.java	100.00% <ø> (ø)
... and 237 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 65f449b...3125416. Read the comment docs.

[anirudha]

Lgtm