convert last java file to .kt + part fix warnings

[Sharabaddin]

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Please make sure that you are using feature branch, since all the WiFi Analyzer changes are done on the feature branch!

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What does this implement/fix? Please describe.

• Convert last java file fix error +part fix warnings
  Does this close any currently open issues?
• no

Additional context

• Add any other context about the pull request.

Where has this been tested?

• Operating System: android 9
• Platform: android 9
• Target Platform: android 9
• Toolchain Version: android studio 4.1.1
• SDK Version: android 9

[codecov]

Codecov Report

Merging #326 (7f230a5) into feature (faa6f6b) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             feature     #326   +/-   ##
==========================================
  Coverage      91.20%   91.20%           
  Complexity       874      874           
==========================================
  Files            126      126           
  Lines           2250     2250           
  Branches         223      223           
==========================================
  Hits            2052     2052           
  Misses            71       71           
  Partials         127      127           

[VREMSoftwareDevelopment]

There is no point to convert this file since it is part of https://github.com/jjoe64/GraphView
There is a PR waiting to be approved and merged: jjoe64/GraphView#412