Raise minSdkVersion from 21 to 26 in the next major release

[0xadam-brown]

Summary

We plan to raise the minimum supported Android SDK version from 21 (Lollipop 5.0) to 26 (Oreo 8.0) in the next major version of sentry-android.

We're opening this issue early so the community can share feedback or raise concerns before the change lands.

Motivation

Android 5.x–7.x devices represent a small and declining share of the active install base. Internal telemetry from Sentry's own data shows that the vast majority of SDK consumers already target API 26+ in practice.

Raising the floor to 26 lets us:

• Reduce testing and maintenance surface — dropping five API levels from our test matrix lets us focus CI and development effort on the versions our users actually run.
• Remove version-check workarounds — lets us remove compatibility code paths for pre-26 behavior.
• Unblock future dependency upgrades — key dependencies in the ecosystem are raising their floors (e.g. OkHttp 5.x requires API 26+). Aligning our minimum lets us adopt newer versions without holding back the entire SDK.

Timeline

This change will ship in the next major version of the SDK. It will not affect any 8.x release. There is no fixed date yet.

What this means for you

If your app's own minSdkVersion is already 26 or higher, no action is needed.

If your app still targets API 21–25, you will need to either:

1. Stay on the latest 8.x release, or
2. Raise your own minSdkVersion before upgrading.

[linear-code]

JAVA-547