Update AppFunctionPackageMetadata constructor visibility

- Hide legacy AppFunctionPackageMetadata constructor and make new constructor public
- Hide components property in AppFunctionMetadata since it's now part of AppFunctionPackageMetadata
- Unhide name and packageMetadata properties in AppFunctionMetadata. Since these are set in the new public constructor, they should be accessible.

Relnote: Update `AppFunctionPackageMetadata` constructor
Test: ./appfunctions/local_tests.sh
Bug: 508188326
Change-Id: I096f7901d6ca95efb6cd376d443f7ab5667c8020