feat(android): add progress bar

[GitToTheHub]

Platforms affected

Android

Motivation and Context

• PR feat(android): add page loading progress bar #1073 added the same implementation. The PR got a little bit noisy, so this is why this PR was created.
• The progress bar can by hidden by hideloadingindicator. The name is hold generic, so it don't presumes a spinner or progress bar.

Description

• The progress bar is enabled by default but can be hidden by the option hideloadingindicator.
• Superseds feat(android): add page loading progress bar #1073

Generated-By: GPT-5.6 Terra

Sample

Android 10

Testing

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

[MaximBelov]

Test app for this, pinned to 1aaf3234:
https://github.com/MaximBelov/cordova-iab-pr1169-loadingindicator-demo

Tested on Android 16. When the server is slow to respond the bar sits at 10% for the whole wait without moving, and when only subresources are slow it disappears while the page is still loading.

[GitToTheHub]

If no one has any objections I would merge this