[SafetyCenter] Restructure SafetyCenterManager APIs in response to API Council...

[SafetyCenter] Restructure SafetyCenterManager APIs in response to API Council feedback and Refactor test API to override SafetyCenterConfig entirely

* Rename sendSafetyCenterUpdate -> setSafetySourceData
* Rename getLastSafetyCenterUpdate -> getSafetySourceData
* Rename clearSafetyCenterData -> clearAllSafetySourceData
* Separate out safety source id from SafetySourceData, so it is
  clear what is being "set" in setSafetySourceData and SafetySourceData
  is now simply a data object that can belong to any source.
* Add an event object while setting data, so Safety Center knows why
  data was set (this was touched upon in API council feedback meeting,
  in particular with receiving data as a result of refresh broadcasts).
* Other APIs have javadoc changes and order rearrangement (to group
  source and ui APIs) only, no logic changes.

Test: atest CtsSafetyCenterTestCases
Bug: 219195246
Bug: 219194447
Bug: 219078602
Bug: 218852160
Bug: 219194453
Bug: 217944317
Change-Id: Icdc839c7a35f0c10013a3b4af37db088995c0a40
Merged-In: Icdc839c7a35f0c10013a3b4af37db088995c0a40