fix: add WebViewAssetloader to default allow list

[NiklasMerz]

Platforms affected

Android

Motivation and Context

Addresses issues in #1217

Closes #1217

Description

With the introduction of the WebViewAssetloader #1137 and the Allow List Plugin #1138 we need to add the origin / href the app is running to the allowlist.

Testing

Create a blank new app with one plugin

cordova create test
cd test
cordova platform add https://github.com/apache/cordova-android#webviewassetloader-allowlist
cordova plugin add cordova-plugin-file
cordova run android

These steps will produce the hello world cordova app that should show "deviceready" with this pr. See issue.

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[codecov-commenter]

Codecov Report

Merging #1275 (7f5fbad) into master (3e870e3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1275   +/-   ##
=======================================
  Coverage   73.26%   73.26%           
=======================================
  Files          21       21           
  Lines        1646     1646           
=======================================
  Hits         1206     1206           
  Misses        440      440           

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[erisu]

LGTM