Google will require developer verification to install Android apps, including sideloading

Developer blocked: Package Installer
Added in version 36.1

DEVELOPER_VERIFICATION_FAILED_REASON_DEVELOPER_BLOCKED

public static final int DEVELOPER_VERIFICATION_FAILED_REASON_DEVELOPER_BLOCKED

DEVELOPER_VERIFICATION_FAILED_REASON_NETWORK_UNAVAILABLE

public static final int DEVELOPER_VERIFICATION_FAILED_REASON_NETWORK_UNAVAILABLE