add text to spinner when click on space member (dm)

[fedrunov]

Type of change

• Feature
• Bugfix
• Technical
• [] Other :

Content

add text to spinner when selecting person to start dm via space people list

Motivation and context

closes #4305

Screenshots / GIFs

Tests

• select space
• select "people" tab
• press fab
• select a person (there shouldn't be already created dm with this person)

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[github-actions]

Unit Test Results

114 files  +  4  114 suites  +4   1m 15s ⏱️ -20s
201 tests +  6  201 ✔️ +  6  0 💤 ±0  0 ❌ ±0 
674 runs  +24  674 ✔️ +24  0 💤 ±0  0 ❌ ±0 

Results for commit 8ae130c. ± Comparison against base commit 3aac59a.

♻️ This comment has been updated with latest results.

[bmarty]

LGTM, but can you add a small file for the changelog please?

[bmarty]

thanks!