Revisit all xml drawables files for Dark Mode audit

[MohitGupta121]

Explanation

Revisit all xml drawables files for Dark Mode audit:

• Prohibited use of color other than component_colors in xml drawables file except vector assets, graphics- added regex check
• Remove unused Drawables files

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)
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[MohitGupta121]

@BenHenning PTAL, Thanks.

As I talk to Rajat in chat and he said we only keep use of component_color in all xml files (include drawables, layouts) but except images, graphics, icons, vector assets and also add regex for all xml.

So in this PR I do all these things, and added separate regex check for drawables and layout. Is it fine?

[BenHenning]

Apologies @MohitGupta121 will need to look at this tomorrow.

[MohitGupta121]

@BenHenning no problem totally fine.

[BenHenning]

Thanks @MohitGupta121. This LGTM!

[oppiabot]

Unassigning @BenHenning since they have already approved the PR.

[oppiabot]

Hi @MohitGupta121, this PR is ready to be merged. Please address any remaining comments prior to merging, and feel free to merge this PR once the CI checks pass and you're happy with it. Thanks!