Nit changes

[rt4914]

Explanation

This PR does not contain any issue number and is a part of #700

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.
• The PR is assigned to an appropriate reviewer in both the Assignees and the Reviewers sections.

[rt4914]

@aggarwalpulkit596 This PR has been assigned to you for review considering that you are a regular contributor to Oppia-Android and that means that other than code-contributor it would be nice for you to increase your expertise as code-reviewer too. Thanks. Mainly you need to run the test test cases and see if they are passing.

[aggarwalpulkit596]

LGTM