refactor(samples): Convert main screen to Jetpack Compose

[markushi]

📜 Description

Converts the MainActivity from Java to Kotlin, categorizing all our buttons a bit nicer too.

Also fixes a missing scroll detection bug for Jetpack Compose.

requires #5016 to be merged first.

💡 Motivation and Context

Modernizes the sample app to use Kotlin, which is now the recommended language for Android development. This makes the sample more representative of current best practices and simplifies future enhancements.

💚 How did you test it?

Manual testing of the sample app to ensure functionality remains unchanged.

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

[github-actions]

Semver Impact of This PR

🟢 Patch (bug fixes)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

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Bug Fixes 🐛

• Establish native exception mechanisms by supervacuus in #5052

Internal Changes 🔧

• (android) Update targetSdk to API 36 (Android 16) by markushi in #5016
• (ci) Write permission for statuses in changelog preview by supervacuus in #5053

• (samples) Convert main screen to Jetpack Compose by markushi in #5017

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_{🤖 This preview updates automatically when you update the PR.}

[sentry]

Bug: The file copy loop incorrectly writes the entire buffer instead of the number of bytes read, potentially corrupting the output file with garbage data from previous reads.
_{Severity: MEDIUM}

Suggested Fix

Capture the number of bytes returned by inputStream.read(bytes) into a length variable. Then, call outputStream.write(bytes, 0, length) to ensure only the valid bytes that were just read are written to the output stream.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location:
sentry-samples/sentry-samples-android/src/main/java/io/sentry/samples/android/MainActivity.kt#L153

Potential issue: The file copy logic reads from an `inputStream` into a `bytes` buffer
but does not use the return value of `inputStream.read(bytes)`, which indicates the
actual number of bytes read. Instead, it calls `outputStream.write(bytes)`, which writes
the entire buffer. On the final read, if the remaining data is smaller than the buffer
size, the buffer will contain valid data followed by stale data from the previous
iteration. Writing the full buffer appends this garbage data to the output file,
resulting in a corrupted file attachment for every Sentry event.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	306.20 ms	353.86 ms	47.66 ms
Size	1.58 MiB	2.19 MiB	620.06 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
dba088c	365.46 ms	366.31 ms	0.85 ms
d15471f	315.20 ms	370.22 ms	55.02 ms
fc5ccaf	256.80 ms	322.36 ms	65.56 ms
806307f	357.85 ms	424.64 ms	66.79 ms
ee747ae	415.92 ms	470.15 ms	54.23 ms
694d587	312.37 ms	402.77 ms	90.41 ms
fcec2f2	311.35 ms	384.94 ms	73.59 ms
ee747ae	405.43 ms	485.70 ms	80.28 ms
d15471f	310.66 ms	368.19 ms	57.53 ms
abf451a	332.82 ms	403.67 ms	70.85 ms

App size

Revision	Plain	With Sentry	Diff
dba088c	1.58 MiB	2.13 MiB	558.99 KiB
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
fc5ccaf	1.58 MiB	2.13 MiB	557.54 KiB
806307f	1.58 MiB	2.10 MiB	533.42 KiB
ee747ae	1.58 MiB	2.10 MiB	530.95 KiB
694d587	1.58 MiB	2.19 MiB	620.06 KiB
fcec2f2	1.58 MiB	2.12 MiB	551.51 KiB
ee747ae	1.58 MiB	2.10 MiB	530.95 KiB
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
abf451a	1.58 MiB	2.20 MiB	635.29 KiB

Previous results on branch: markushi/feat/restructure-sample-app

Startup times

Revision	Plain	With Sentry	Diff
d499045	350.63 ms	394.56 ms	43.93 ms
0f80cc7	318.59 ms	363.17 ms	44.58 ms

App size

Revision	Plain	With Sentry	Diff
d499045	1.58 MiB	2.19 MiB	620.05 KiB
0f80cc7	1.58 MiB	2.19 MiB	620.05 KiB

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with Cloud Agents, enable Autofix in the Cursor dashboard.}

[cursor]

API 23+ method used with minSdk 21

Low Severity

The resources.getColor(int, Theme) method requires API 23+, but the project's minSdk is 21. This causes a NoSuchMethodError crash on API 21-22 devices when MainActivity launches. The @SuppressLint("NewApi") annotation suppresses the lint warning but doesn't prevent the runtime crash. Consider using ContextCompat.getColor() or Compose's colorResource() for backward compatibility.