feat: better composer height calculation

[diegolmello]

Proposed changes

This is an improved version of #5514

KeyboardAccessoryView provides onHeightChanged, which makes use of onLayout based on the actual native component.
There's no need to patch react-native-ui-lib or to wrap the composer in another View.

Issue(s)

How to test or reproduce

Screenshots

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves a current function)
• New feature (non-breaking change which adds functionality)
• Documentation update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have added necessary documentation (if applicable)
• Any dependent changes have been merged and published in downstream modules

Further comments

NATIVE-478