[SDK-565] Remove the unused encryptionEnforced field from IterableConfig

[franco-zalamena-iterable]

📝 Summary

Deletes the encryptionEnforced field from IterableConfig. It has had no setter and no reader since 3.5.5 — a merge reinstated the field in 3.6.0 without its setter, and it has sat unsettable and unread ever since.

🎟️ Jira Ticket: SDK-565

📖 Description

3.5.5 removed this option and its public Builder.setEncryptionEnforced(boolean) (#849), and the published CHANGELOG says so:

Removed encryptionEnforced parameter from IterableConfig as data is now always encoded for security

Then 022ea9537 (the unknown-user merge, which had forked before the removal) reinstated the field, the builder field and the constructor assignment — but not the setter. A field with no way to set it isn't a design, it's a half-resolved merge conflict. Tag scan of IterableConfig.java confirms the shape: 3.5.5–3.5.10 → 0 occurrences, 3.6.0 onward → 3. So that CHANGELOG line has been untrue for four minor versions. Deleting the field makes the shipped record honest again.

This is not a public API change. final boolean encryptionEnforced; had no access modifier, so it was package-private; the builder's copy was private. No setter, no getter, no read anywhere in the SDK, iterableapi-ui, or the sample app. Nothing outside the package could read it, write it, or see it in autocomplete, so removal breaks no caller — source or binary — and there is no deprecation window to honour.

Why remove rather than deprecate (the Jira summary says "deprecate"): @Deprecated is a message to callers, and a package-private field with no accessors has none — it would warn nobody. The removal was also already announced to customers 20 months ago, so starting a fresh deprecation clock on it doesn't make sense. This means SDK-647, filed as the "removal half" of a deprecate-then-remove sequence, has no Android work left; I'll close or repoint it separately.

Storage behaviour is untouched. setKeychainEncryption(boolean) and setDecryptionFailureHandler(...) are the live options and are unaffected.

🧪 How to test?

./gradlew :iterableapi:testDebugUnitTest :iterableapi:checkstyle

There is no teeth check for the deletion itself, and the tests prove nothing about it. Nothing reads the field, so no test can fail while it is merely present — that's the whole finding. Removal is inert by inspection, not by assertion.

What the new encryptionEnforcedIsNotPartOfTheConfiguration test does have teeth against is a future re-add, which is the failure mode that actually happened here. Re-adding the three lines this PR deletes fails it:

com.iterable.iterableapi.IterableConfigTest > encryptionEnforcedIsNotPartOfTheConfiguration FAILED
    java.lang.AssertionError: encryptionEnforced was reintroduced: [encryptionEnforced, encryptionEnforced]

A reflection guard is admittedly a weak instrument. It's here because nothing in the build is a strong one: there's no metalava / japicmp / binary-compatibility-validator and no checked-in API snapshot, so any merge can silently reinstate removed API. That gap is worth its own infra ticket; this PR just guards the one symptom.

Full iterableapi suite and checkstyle pass locally.

🧾 Changelog

• Removed the encryptionEnforced field from IterableConfig. No action required. 3.5.5 announced this option as removed and deleted its public setter, but a merge reinstated the field — without the setter — in 3.6.0, where it has sat unsettable and unread ever since. There has been no way to set it and no effect on SDK behaviour since 3.5.5, so no app can be affected. Storage behaviour is unchanged: use setKeychainEncryption(boolean) to control whether stored user data is encrypted, and setDecryptionFailureHandler(...) to be notified when the SDK cannot decrypt it.

📹 Loom recording if applicable

N/A — no observable behaviour change.

🐞 Github Issues solved

None.

📚 Docs PR if applicable

Covered on the September release branch (docs/sdk/september-release): a 3.11.0 release-notes bullet plus a "Removed: the unused encryptionEnforced option" subsection under Upgrading to 3.11.0. That branch's PR covers the whole September release rather than this ticket alone.

Out of scope

React Native still ships a public, documented, tested encryptionEnforced (IterableConfig.ts:330, serialized at :485) that neither native module reads — git grep -i encryptionenforced -- android ios on RN master is empty. That's the surface where the "false sense of security" is real, and where removal genuinely would be source-breaking. Needs its own RN ticket; this PR doesn't affect RN, since the bridge already discards the key.