Make com.amplitude.android.Amplitude return com.amplitude.core.platform.Timeline

[asherepenko]

Right now android's `Amplitude uses android's package Timeline, wich is final and can't be extended:

    override fun createTimeline(): com.amplitude.android.Timeline {
        return Timeline(configuration.sessionId).also { it.amplitude = this }
    }

It either has to be com.amplitude.core.platform.Timeline or com.amplitude.android.Timeline should be open class

Expected Behavior

Current Behavior

Possible Solution

Steps to Reproduce

Environment

• Unity Plugin Version:
• Device:
• Device OS and Version:

[izaaz]

@asherepenko - can you please share what you're trying to do by extending the Timeline class? I can check if we can make that class open but wanted to understand the usecase to see if there are other ways the same functionality can be achieved.