Which partitions are encrypted by default android disk encryption?

If the device implementation supports a secure lock screen reporting "true" for KeyguardManager.isDeviceSecure(), and is not a device with restricted memory as reported through the ActivityManager.isLowRamDevice() method, then the device MUST support full-disk encryption of the application private data (/data partition), as well as the application shared storage partition (/sdcard partition) if it is a permanent, non-removable part of the device.

For device implementations supporting full-disk encryption and with Advanced Encryption Standard (AES) crypto performance above 50MiB/sec, the full-disk encryption MUST be enabled by default at the time the user has completed the out-of-box setup experience. If a device implementation is already launched on an earlier Android version with full-disk encryption disabled by default, such a device cannot meet the requirement through a system software update and thus MAY be exempted.