Fixes #2326: A11y changes for Topic Practice Tab

[rt4914]

Explanation

Fixes #2326
All the issues mentioned inside the original issue were already passing but I found a new error which is related to min-clickable-height. Therefore this PR updates the minHeight to 48dp.

Solved issue

Checklist

• The PR title starts with "Fix #bugnum: ", followed by a short, clear summary of the changes. (If this PR fixes part of an issue, prefix the title with "Fix part of #bugnum: ...".)
• The PR explanation includes the words "Fixes #bugnum: ..." (or "Fixes part of #bugnum" if the PR only partially fixes an issue).
• The PR follows the style guide.
• The PR does not contain any unnecessary auto-generated code from Android Studio.
• The PR is made from a branch that's not called "develop".
• The PR is made from a branch that is up-to-date with "develop".
• The PR's branch is based on "develop" and not on any other branch.
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[anandwana001]

LGTM

[oppiabot]

Unassigning @anandwana001 since they have already approved the PR.