Empty moduleType disallows all RPC requests after ignition cycle

[Jack-Byrne]

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Bug Report

When a moduleType is left empty as such:

        "app_policies": {
            "default": {
                "keep_context": false,
                "steal_focus": false,
                "priority": "NONE",
                "default_hmi": "NONE",
                "groups": ["Base-4", "RemoteControl"],
                "RequestType": [],
                "RequestSubType": [],
                "moduleType": []
            },

The process of saving the cached policy table to policy.sqlite does not account for an empty moduleType array. This leaves the moduleType field in the SQL DB empty so when core is cycled and the SQL Db is read into memory again, moduleType is marked as missing and all RC rpcs are disallowed.

Reproduction Steps

1. Change preloaded pt app_policies default to object above.
2. Start core, stop core, restart core
3. Connect RC app, put in full, and send any RC rpc

Expected Behavior

All RC RPCs for all moduleTypes should return success.

Observed Behavior

All module types for all RC requests return disallowed.

OS & Version Information

• OS/Version: Ubuntu
• SDL Core Version: Develop
• Testing Against: SPT