[GSoC] migrated AnkiStatsTaskHandler.createReviewSummaryStatistics() to suspend function

[thedroiddiv]

This PR is a continuation of #11556

Purpose / Description

AsyncTask to coroutines migration

Fixes

Fixes a part of #7108

How Has This Been Tested?

Unit tested and runs as expected on Realme 6i API 30 and Pixel 3a Emulator API 31

Affected part is the bottom 1 line statistics

before

after

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration (SDK version(s), emulator or physical, etc)

Learning (optional, can help others)

Describe the research stage

Links to blog posts, patterns, libraries or addons used to solve this problem

Checklist

Please, go through these checks before submitting the PR.

• You have not changed whitespace unnecessarily (it makes diffs hard to read)
• You have a descriptive commit message with a short title (first line, max 50 chars).
• Your code follows the style of the project (e.g. never omit braces in if statements)
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[lukstbit]

After solving the raised issues, I'm ok with this PR being merged.

[thedroiddiv]

Once it gets merged, I can use the same ext function in #11628 and others as well.

[thedroiddiv]

And also I thought of com.ichi2.async to be the more appropriate package for it. If there are any comments, let me know.

[ShridharGoel]

Looks good.