Partially Fixes #4194: Added dark mode support to DrawerFragment, ConceptCardFragment and AudioFragment.

[Akshatkamboj14]

Explanation

Partially Fixes #4194

Drawer Fragment: https://xd.adobe.com/view/c05e9343-60f6-4c11-84ac-c756b75b940f-950d/screen/eb119ee3-033f-4757-8aee-7ea234d6f126/specs/

Concept Card Fragment: https://xd.adobe.com/view/c05e9343-60f6-4c11-84ac-c756b75b940f-950d/screen/2ee531cf-c358-4a7d-b9dd-b772b51c3d3c/specs/

Audio Fragment: https://xd.adobe.com/view/c05e9343-60f6-4c11-84ac-c756b75b940f-950d/screen/d67b268b-f6d9-434f-8897-24a2b13ccd84/specs/

-> This PR is Broken into two pieces, First-one is to Add dark mode support to DrawerFragment, ConceptCardFragment, and AudioFragment. The second is to Add dark mode support to HomeActivity and RevisionCardActivity (this is to be done by @bhaktideshmukh)

Default	Dark Mode
	)

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).

For UI-specific PRs only

If your PR includes UI-related changes, then:

• Add screenshots for portrait/landscape for both a tablet & phone of the before & after UI changes
• For the screenshots above, include both English and pseudo-localized (RTL) screenshots (see RTL guide)
• Add a video showing the full UX flow with a screen reader enabled (see accessibility guide)
• Add a screenshot demonstrating that you ran affected Espresso tests locally & that they're passing

[Akshatkamboj14]

I have a doubt in the audio_fragment.xml as there is textView that recently got added and the mocks are not up to date with the new text view, Please tell me if I have to add dark mode to that as well?

[rt4914]

@Akshatkamboj14 File a separate issue for the view/UI which does not have dark-mode implemented. That way it will be helpful in following cases:

1. We can ask designers to create mock and solve in separate PR
2. If we decide to solve this without mock than also its nice to track separately which issue got solved without mock and if needed to revert in future, it will be easy.

[Akshatkamboj14]

Okay sure @rt4914

[Akshatkamboj14]

Done @rt4914
https://github.com/oppia/oppia-android/issues/4561

[Akshatkamboj14]

Hey @rt4914 PTAL, Thanks.

[rt4914]

@Akshatkamboj14 Nice work. One minor change

[rt4914]

@Akshatkamboj14 Merge with latest develop.

FYI you might need to remerge as a lot of conflicting PRs are getting merged daily.

[rt4914]

LGTM, Thanks.