Android openness tightening: sideloading lockdown, custom ROMs harder, Advanced Protection pause

Google plans to require developer verification for all sideloaded apps by late 2026, with no opt-out. ADB remains as workaround. Google is refining Advanced Protection with a temporary pause feature (3-hour auto-re-enable) ahead of September 2026 rollout. Additionally, Google plans to exempt sanctioned nations from developer verification. New: Google is also making it harder to build custom ROMs for Pixel phones – kernel source code now requires manual request with multi-week delays, further tightening control. This is a fundamental shift in Android's open philosophy.