Remove usage of requireNonNullElseGet (Android compat)

[robinst]

Fixes #366

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.94%. Comparing base (4710917) to head (5bb93e7).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #369   +/-   ##
=========================================
  Coverage     94.94%   94.94%           
  Complexity      252      252           
=========================================
  Files           138      138           
  Lines          4469     4471    +2     
  Branches        645      646    +1     
=========================================
+ Hits           4243     4245    +2     
  Misses          122      122           
  Partials        104      104           

Files with missing lines	Coverage Δ
...rk/src/main/java/org/commonmark/parser/Parser.java	98.61% <100.00%> (+0.03%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.