Updated the BufferStreamsDemoApp UI to jetpack compose.

The project is no longer using Java and now the MainActivity uses
Kotlin, calling JNI from Kotlin is fairly simiar.

Currently there are 3 empty demo screens, the first demo screen will
call a JNI function but there is no support for logs.

Bug: 296272152
Test: Built and ran on device.
Change-Id: I92f0951899fb6379e1506abdc8e1d67002433787