Remove unwanted condition from dark-mode wiki (#5117)

<!-- READ ME FIRST: Please fill in the explanation section below and
check off every point from the Essential Checklist! -->
## Explanation

As per suggested by @rt4914 in this issue
[comment](#5114 (comment))
we have to remove that line from wiki to close that issue.

<!--
- Explain what your PR does. If this PR fixes an existing bug, please
include
- "Fixes #bugnum:" in the explanation so that GitHub can auto-close the
issue
  - when this PR is merged.
  -->

## Essential Checklist
<!-- Please tick the relevant boxes by putting an "x" in them. -->
- [ ] 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](https://github.com/oppia/oppia-android/tree/develop/scripts/assets)
files have their rationale included in the PR explanation.
- [x] The PR follows the [style
guide](https://github.com/oppia/oppia-android/wiki/Coding-style-guide).
- [x] The PR does not contain any unnecessary code changes from Android
Studio
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#undo-unnecessary-changes)).
- [x] The PR is made from a branch that's **not** called "develop" and
is up-to-date with "develop".
- [x] The PR is **assigned** to the appropriate reviewers
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#clarification-regarding-assignees-and-reviewers-section)).

## For UI-specific PRs only
<!-- Delete these section if this PR does not include UI-related
changes. -->
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](https://github.com/oppia/oppia-android/wiki/RTL-Guidelines))
- Add a video showing the full UX flow with a screen reader enabled (see
[accessibility
guide](https://github.com/oppia/oppia-android/wiki/Accessibility-A11y-Guide))
- Add a screenshot demonstrating that you ran affected Espresso tests
locally & that they're passing

wiki/Dark-Mode.md

@@ -112,5 +112,4 @@ These rules were followed while implementing dark-mode designs in android app:
 - Ensure that the naming of new colors across all files should follow the rules mentioned [above](https://github.com/oppia/oppia-android/wiki/Dark-Mode#knowing-the-convention).
 - If any new color is getting introduced in the `color_defs.xml` file, then treat it as a red flag and keep a close eye on why it is getting introduced? Why can't any of the existing colors be used? Has this been approved by the design team?
 - If any new color palette is getting introduced in `color_palette.xml` keep a close eye on that to make sure that there is no similar color palette already defined in `color_palette.xml` light/dark files. If there is a similar color palette, can you rename the existing color_palette such that it can be used on existing places as well as new places?
-- Other than thumbnails and icons in `mipmap` and `drawable` folder, all other places should reference color code from `component_colors.xml` file only. There should not be any direct usage of color from `color_palette.xml` or `color_defs.xml` or any other file. (Note: there is an issue filed at [#5114](https://github.com/oppia/oppia-android/issues/5114) to do this automatically via a CI check, but until that issue is resolved, this needs to be checked manually.)
 - Hardcoded-colors should only be mentioned in icons/thumbnails of `mipmap` and `drawable`folder and in the `color_defs.xml` file.