CLI-1668: added content type header

[kalindi-adhiya]

Motivation

Fixes #NNN

Proposed changes

Alternatives considered

Testing steps

1. Follow the contribution guide to set up your development environment or download a pre-built acli.phar for this PR.
2. If running from source, clear the kernel cache to pick up new and changed commands: ./bin/acli ckc
3. Check for regressions: (add specific steps for this pr)
4. Check new functionality: (add specific steps for this pr)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.07%. Comparing base (6695493) to head (41459fc).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1946      +/-   ##
============================================
+ Coverage     92.05%   92.07%   +0.02%     
- Complexity     1894     1903       +9     
============================================
  Files           122      122              
  Lines          6959     6978      +19     
============================================
+ Hits           6406     6425      +19     
  Misses          553      553              

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[github-actions]

Try the dev build for this PR: https://acquia-cli.s3.amazonaws.com/build/pr/1946/acli.phar

curl -OL https://acquia-cli.s3.amazonaws.com/build/pr/1946/acli.phar
chmod +x acli.phar