Why is ECB mode used on the keys?

[bradley-curran]

I don't understand why ECB is used for the keys but CBC for the values.

[behelit]

Android Studio actually complains about using ECB now and recommends removing it.
I think it may have been there originally to offer some differentiation in encoding methods for keys and values? or possibly even a typo. In any case it shouldn't be used

ECB encryption mode should not be used (was "AES/ECB/PKCS5Padding") less... (Ctrl+F1)
Cipher#getInstance should not be called with ECB as the cipher mode or without setting the cipher mode because the default mode on android is ECB, which is insecure.