https://source.android.com/docs/security/features/encryption/file-based#enabling-file-based-encryption
FBE is enabled by adding the option fileencryption=contents_encryption_mode[:filenames_encryption_mode[:flags]] to the fs_mgr_flags column of the fstab line for userdata. This option defines the encryption format on internal storage. It contains up to three colon-separated parameters: maybe just removing this from fstab would make it easier to recover from things
