Make deviceconfig values updatable

Values need to be updatable specifically for killswitches and testing.

Also:
- delays initialization of values till they are needed (by collection type)
- used DeviceConfig#getProperties to grab all properties at once and reduce work
- elimnate the use of contains index in the test listener to avoid searching twice

Bug: 338221151
Test: With next CL
Flag: EXEMPT - day-to-day bugfix
Change-Id: If1e98afeed48ca75afdd7bd4cbe97ee2bd3a327b
4 files changed