Implement RateLimiter disable via DeviceConfigs for testing

- rate limiter subscribe to profiling namespace and update enabled field when changed
- initialize rate limiter when first used

Not yet addressed: ensuring config can only be set in testing

Bug: 293957254
Test: change value via adb, confirm it's updated in rate limiter
Change-Id: I66cbff833a8fc3d0db21bb01a68c0a9379100a5e