Explain the app's data access from the system Privacy Dashboard

[hayaksi1]

Content

Since Android 12 the system Privacy Dashboard offers a "See why this app accessed your data" link for
any app that declares an activity for android.intent.action.VIEW_PERMISSION_USAGE. Element declares
none, so the link is simply absent.

This adds one. It is a static screen listing the four runtime permissions the application asks for —
camera, microphone, location, notifications — with the feature each one serves. It holds no state,
reads nothing, and is guarded by android:permission="android.permission.START_VIEW_PERMISSION_USAGE"
so only the permission controller can start it.

The wording sticks to what the code actually does today, so it needs revisiting if a permission is
added or repurposed. aapt dump badging is unchanged, since the new activity is not launchable and
adds no uses-permission.

Motivation and context

Part of #943.

Screenshots / GIFs

The screen is covered by a @PreviewsDayNight preview, so it appears in the file diff. Note that
:tests:uitests deliberately excludes :app, so there is no Paparazzi golden for it.

Tests

• app/src/test/.../permissions/PermissionRationaleActivityTest.kt — asserts the activity stays
  declared, keeps answering VIEW_PERMISSION_USAGE, and keeps its START_VIEW_PERMISSION_USAGE
  guard. The entry point is a manifest declaration and nothing in the code would notice if it were
  dropped or exported unguarded, so that is what the test watches.
  A queryIntentActivities test would be the natural form, but Robolectric in :app resolves against
  org.robolectric.default rather than the merged manifest — :app does not set
  unitTests.isIncludeAndroidResources, which is also why :tests:uitests cannot depend on it.
• ./gradlew :app:testGplayDebugUnitTest :app:compileGplayDebugKotlin :app:ktlintCheck :app:detekt — green.

Tested devices

• Physical
• Emulator
• OS version(s): the screen itself renders from API 24; the Privacy Dashboard entry point needs API 31+

Checklist

• I am aware of the etiquette.
• This PR was made with the help of AI:
  • Yes. In this case, please request a review by Copilot.
  • No.
• Changes have been tested on an Android device or Android emulator with API 24
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request title will be used in the release note, it clearly defines what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• You've made a self review of your PR

[github-actions]

Thank you for your contribution! Here are a few things to check in the PR to ensure it's reviewed as quickly as possible:

• If your pull request adds a feature or modifies the UI, this should have an equivalent pull request in the Element X iOS repo unless it only affects an Android-only behaviour or is behind a disabled feature flag, since we need parity in both clients to consider a feature done. It will also need to be approved by our product and design teams before being merged, so it's usually a good idea to discuss the changes in a Github issue first and then start working on them once the approach has been validated.
• Your branch should be based on origin/develop, at least when it was created.
• The title of the PR will be used for release notes, so it needs to describe the change visible to the user.
• The test pass locally running ./gradlew test.
• The code quality check suite pass locally running ./gradlew runQualityChecks.
• If you modified anything related to the UI, including previews, you'll have to run the Record screenshots GH action in your forked repo: that will generate compatible new screenshots. However, given Github Actions limitations, it will prevent the CI from running temporarily, until you upload a new commit after that one. To do so, just pull the latest changes and push an empty commit.

[bmarty]

Thanks @hayaksi1 . Can you add a screenshot of the screen to the PR description or in a comment so that I can ask product what they think about it?

[CLAassistant]

All committers have signed the CLA.

[hayaksi1]

@bmarty Done.