Android: use the right selection indexes when deleting text.

[jmartinesp]

• Backspacing was not updating the selection and it could become out of sync causing https://github.com/element-hq/element-x-android/issues/2784.
• Forward deletion wasn't sending composer indexes, it was using Android editor's ones.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 67.56757% with 12 lines in your changes are missing coverage. Please review.

Project coverage is 87.25%. Comparing base (288c5de) to head (ef52f45).

Files	Patch %	Lines
.../wysiwyg/inputhandlers/InterceptInputConnection.kt	68.57%	3 Missing and 8 partials :warning:
...roid/wysiwyg/internal/viewmodel/EditorViewModel.kt	0.00%	0 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #971 +/- ## ============================================ - Coverage 88.47% 87.25% -1.22% Complexity 449 449 ============================================ Files 227 154 -73 Lines 23998 20149 -3849 Branches 753 759 +6 ============================================ - Hits 21232 17581 -3651 + Misses 2458 2255 -203 - Partials 308 313 +5 ``` | [Flag](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | Coverage Δ | | |---|---|---| | [uitests](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `64.58% <67.56%> (-9.42%)` | :arrow_down: | | [uitests-android](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `64.58% <67.56%> (+0.09%)` | :arrow_up: | | [uitests-ios](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `?` | | | [unittests](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `86.59% <0.00%> (-0.29%)` | :arrow_down: | | [unittests-android](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `41.71% <0.00%> (-0.17%)` | :arrow_down: | | [unittests-ios](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `?` | | | [unittests-react](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `87.99% <ø> (ø)` | | | [unittests-rust](https://app.codecov.io/gh/matrix-org/matrix-rich-text-editor/pull/971/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org) | `89.64% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=matrix-org#carryforward-flags-in-the-pull-request-comment) to find out more.

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[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[jmartinesp]

Added a test in https://github.com/matrix-org/matrix-rich-text-editor/pull/971/commits/ef52f45fa9b93c4d6cc89f9dec4952fb8106e2aa so we won't have that regression in the future.