Fixes #4443: Talkback reader reads blank on empty resume lesson summary

[vrajdesai78]

Explanation

Fixes #4443: Handles edge case where the summary for resume lesson is empty.

Essential Checklist

• The PR title and explanation each start with "Fix #bugnum: " (If this PR fixes part of an issue, prefix the title with "Fix part of #bugnum: ...".)
• Any changes to scripts/assets files have their rationale included in the PR explanation.
• The PR follows the style guide.
• The PR does not contain any unnecessary code changes from Android Studio (reference).
• The PR is made from a branch that's not called "develop" and is up-to-date with "develop".
• The PR is assigned to the appropriate reviewers (reference).

Before

blank-space.mp4

After

accessibility-blank.mp4

Passing Test cases

[rt4914]

@vrajdesai78 PTAL. Thanks.

[oppiabot]

Hi @vrajdesai78, I'm going to mark this PR as stale because it hasn't had any updates for 7 days. If no further activity occurs within 7 days, it will be automatically closed so that others can take up the issue.
If you are still working on this PR, please make a follow-up commit within 3 days (and submit it for review, if applicable). Please also let us know if you are stuck so we can help you!

[vrajdesai78]

Keep this PR open

[vrajdesai78]

When I tried to write test case https://gist.github.com/vrajdesai78/5088cd112ecf3c505ff13b79ac433bd1 it's showing me error as shown below. I have tried to create newTestChecking test to test whether textView is set to ImportantForAccessibility or Not.

[rt4914]

@vrajdesai78 PTAL.

[rt4914]

LGTM, Thanks.