Refator Code to use !is instead of !(<variable> is <type>)

[Ishad-M-I-M]

Purpose

Fixes: ballerina-platform/ballerina-library#2952

Examples

Checklist

• Linked to an issue
• Updated the changelog
• Added tests
• Updated the spec

[codecov]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (98f45ae) 86.50% compared to head (fd3790a) 86.42%.
Report is 5 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main      #44      +/-   ##
============================================
- Coverage     86.50%   86.42%   -0.09%     
+ Complexity      713      706       -7     
============================================
  Files            56       56              
  Lines          3202     3197       -5     
  Branches        355      355              
============================================
- Hits           2770     2763       -7     
- Misses          327      329       +2     
  Partials        105      105              

Files	Coverage Δ
...otoc/builder/syntaxtree/components/Expression.java	77.27% <100.00%> (-2.73%)	⬇️
...lder/syntaxtree/constants/SyntaxTreeConstants.java	100.00% <100.00%> (ø)
.../protoc/builder/syntaxtree/utils/MessageUtils.java	80.12% <100.00%> (-0.37%)	⬇️
...a/protoc/builder/syntaxtree/utils/ServerUtils.java	94.61% <100.00%> (-0.07%)	⬇️

... and 1 file with indirect coverage changes

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