[Rich text editor] Fix composer height and padding

[jonnyandrew]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

• Fix composer padding when it has multiple lines
• Fix composer shape when it has multiple lines

Motivation and context

• [Design review] Improve rich text editor UI #1315

Screenshots / GIFs

Tests

• Step 1
• Step 2
• Step ...

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes have been tested on an Android device or Android emulator with API 23
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/vector-im/element-x-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-x-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

[jonnyandrew]

This change is an unrelated lint fix

[github-actions]

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[sonarcloud]

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0 Security Hotspots
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[codecov]

Codecov Report

Patch coverage: 66.66% and project coverage change: -0.01% ⚠️

Comparison is base (4bf439d) 57.71% compared to head (a772f3d) 57.71%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1316      +/-   ##
===========================================
- Coverage    57.71%   57.71%   -0.01%     
===========================================
  Files         1087     1087              
  Lines        28665    28667       +2     
  Branches      5870     5870              
===========================================
+ Hits         16544    16545       +1     
- Misses        9546     9547       +1     
  Partials      2575     2575              

Files Changed	Coverage Δ
...ent/android/libraries/textcomposer/TextComposer.kt	54.91% <66.66%> (-0.03%)	⬇️

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