During Android Encryption, I lost my device keyboard and OS ask me to enter password? I have Android phone with OS version 4.4, I start encrypt my phone and it started very well. After an hour and restringing several time the device prompt me to "Type password to decrypt storage".

Her is the problem begins, I suspect the system keyboard won't work because it was disabled in settings yesterday and set google keyboard for normal usage, and now I unable to enter password.

Can anybody tell me how can I enable my default keyboard or enter required password ?
First, have a look at the answers to this question.

If none if them works for you and you have access to the recovery, I think you can only wipe data / factory reset your device.

If you don't have access to the recovery, you can still factory reset the device via fastboot with fastboot erase userdata.

Factory resetting your device will delete your data though.