Allow logging Throwable objects in LoggingService

Add APIs to LoggingService to support logging Throwable objects, similar to the Android Log APIs:
https://developer.android.com/reference/android/util/Log#w(java.lang.String,%20java.lang.Throwable)

Currently, developers can use andriod.util.Log.getStackTraceString() and pass the result string in the log message.

Start at the LoggingService entry point and compare its current APIs with the Android Log APIs linked in the issue, especially the Throwable overload. Inspect any existing logging tests if present; done means LoggingService can accept Throwable objects and produce stack-trace information without requiring callers to convert them to strings.

Written by the indexing model from the issue text.