tracinglib: remove -Xmulti-platform

To integrate better with ASfP, remove KMP usage.

Also:

 - Convert java host test to robolectric

 - Replace Kotlin 'internal' usage with @VisibleFor

Test: install CoroutineTracingDemoApp
Test: atest tracinglib-robo-test
Flag: com.android.systemui.coroutine_tracing
Bug: 289353932
Merged-In: Ifff786f94765fec844b64716d3f961c9b49d16b9
Change-Id: Ifff786f94765fec844b64716d3f961c9b49d16b9
26 files changed