I do not know of an app that can change the encryption password on these devices yet, but you can still change it from the command-line. This must be done as root, so you will need to enable root in the developer options, then use
suin the terminal. Note, however, that the syntax has changed. Previously, the command was:
vdc cryptfs changepw password newpassword
Now the command expects an additional parameter, the old password:
vdc cryptfs changepw password default_password newpassword
Currently, the old password parameter is not used (it doesn’t actually have to be the old password, it can be anything), but it must be present for the new password to be interpreted correctly. The command should indicate success by printing:
200 0 0
Yea, it would be nice if it gave helpful error messages, but all you get is cryptic numerical codes. You can verify that the password was set correctly with:
vdc cryptfs verifypw newpassword
If the new password is correct, this command will also print:
200 0 0
In order to set the encryption password correctly and separately from the lock screen, you will want to encrypt the phone, then set your lock screen with a password (opting to require the password at start up), then change the encryption password with the command above. Now the lock screen will be the password you originally selected when you set the lock screen password, but the stronger password will be required to decrypt the device on boot.
Hopefully some of you got here in time to avoid data loss. Thanks for reading!