feat: Simplify android age mocking

[fredrifoUni]

This PR simplifies the Android age mocking and makes it configurable from anywhere in the native code

Example:

// MainActivity.kt
import com.margelo.nitro.playagerangedeclaration.PlayAgeRangeDeclaration
import com.margelo.nitro.playagerangedeclaration.PlayAgeRangeMockConfig

override fun onCreate() {
      ....
      PlayAgeRangeDeclaration.setMockUser(
        PlayAgeRangeMockConfig(
          userStatus = 1,
          ageLower = 13,
          ageUpper = 16,
        )
      )
}

Notes to keep in mind before merging:

• I have only tested the code by modifying it directly in my node_modules folder
• I haven't ran the nitro build script and I don't know if my changes will cause any issues with it.
• I have not bridged any of this code. Hopefully someone experienced with nitro can pick that up at some point.