build: validate local Gradle JDK

[Steadyx]

What changed

Risk

Validation

• ./gradlew qualityCheck
• ./gradlew qualityGate when Android/UI/build behavior changed
• Android Lint attempted for Android-facing changes; any analyzer stall is documented separately
• Focused regression tests added or updated
• git diff --check
• Connected instrumentation run when device behavior changed, or the missing device/emulator is documented

Quality policy

• No baseline, ignoreFailures, broad exclusion, or unrelated threshold relaxation was added
• Any new suppression is declaration-scoped and explained next to the annotation
• No generated files, debug logging, commented-out code, or unrelated formatting churn is included