fix(app-start): Fix detection of foreground app start

[markushi]

Description

Pre Android 15, AppStartMetrics.appLaunchedInForeground uses a LazyEvaluator<Boolean> that only
evaluated ContextUtils.isForegroundImportance() on the first read. Since the read can happen at a later point in time, e.g. during Activity.onCreate() the process importance might have changed by now, and we incorrectly detect foreground / background starts - causing long app starts.

This PR changes the behavior, and we now immediately evaluate the foreground flag. This will make foreground/background app starts pre Android 15 more correct, at the cost of an extra binder call via ContextUtils.isForegroundImportance().

💡 Motivation and Context

Fixes #4693 (pre Android 15)

💚 How did you test it?

Unit Tests.

📝 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.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.

[github-actions]

	Fails
🚫	Please consider adding a changelog entry for the next release.

Instructions and example for changelog

Please add an entry to CHANGELOG.md to the "Unreleased" section. Make sure the entry includes this PR's number.

Example:

## Unreleased

### Fixes

- Fix detection of foreground app start ([#5880](https://github.com/getsentry/sentry-java/pull/5880))

If none of the above apply, you can opt out of this check by adding #skip-changelog to the PR description or adding a skip-changelog label.

Generated by 🚫 dangerJS against df4b9aa

[github-actions]

	Fails
🚫	Please consider adding a changelog entry for the next release.

Instructions and example for changelog

Please add an entry to CHANGELOG.md to the "Unreleased" section. Make sure the entry includes this PR's number.

Example:

## Unreleased

### Fixes

- Fix detection of foreground app start ([#5880](https://github.com/getsentry/sentry-java/pull/5880))

If none of the above apply, you can opt out of this check by adding #skip-changelog to the PR description or adding a skip-changelog label.

Generated by 🚫 dangerJS against df4b9aa

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.51.0 (1)	release

⚙️ sentry-android Build Distribution Settings

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	405.09 ms	496.16 ms	91.07 ms
Size	0 B	0 B	0 B

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
6b019b7	343.31 ms	417.23 ms	73.91 ms
d15471f	342.08 ms	415.44 ms	73.35 ms
8687935	332.52 ms	362.23 ms	29.71 ms
5b1a06b	352.27 ms	413.70 ms	61.43 ms
91bb874	314.47 ms	440.00 ms	125.53 ms
0ee65e9	321.06 ms	361.24 ms	40.18 ms
e63ad34	323.67 ms	390.33 ms	66.67 ms
33a08cc	267.08 ms	340.45 ms	73.37 ms
27d7cf8	397.90 ms	498.65 ms	100.75 ms
ee747ae	405.43 ms	485.70 ms	80.28 ms

App size

Revision	Plain	With Sentry	Diff
6b019b7	0 B	0 B	0 B
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
8687935	1.58 MiB	2.19 MiB	619.17 KiB
5b1a06b	0 B	0 B	0 B
91bb874	1.58 MiB	2.13 MiB	559.07 KiB
0ee65e9	0 B	0 B	0 B
e63ad34	0 B	0 B	0 B
33a08cc	1.58 MiB	2.12 MiB	555.28 KiB
27d7cf8	1.58 MiB	2.12 MiB	549.42 KiB
ee747ae	1.58 MiB	2.10 MiB	530.95 KiB

[0xadam-brown]

Nice!

Approving pending addition of the CHANGELOG entry 👍

[0xadam-brown]

Suggested change

	// Fallback, if not matching ApplicationStartInfo is available
	// Fallback, if no matching ApplicationStartInfo is available