Keystore 2.0: Adopt associated const enum variants.

The aidl to rust generator now generates tuple structs with associated
constants as variants. This patch adjusts the existing Keystore 2.0
codebase to this change.

In the process one more variant was added to the
implement_key_parameter_conversion_to_from_wire! macro and the
indentation was fixed.

Test: keystore2_test
Change-Id: I2639c76d4da7401f6799180e1bfcb3e420341628
4 files changed