Initial values format adjusted

Initial values format adjusted

[Issue#] N/A
[Feature/Bug] N/A
[Problem] Symmetric keys should not hold information about encryption
algorithm. Initial data will be stored as system user but has to be accessible
by ordinary users
[Cause] N/A
[Solution] Symmetric encryption params can be stored separately from key as
data. Encryption params removed from schema. Added permission tag allowing
other users to access system database. XML structure redesigned. Example
updated.

[Verification] Validate example with:
xmllint -schema initial_values.xsd example.xml

Change-Id: I36149b15d6f786e37cec370d632ab74e40efc162