Resolve possible deadlock in Logging

Currently, if the sCleanStaleSessions telecom.Runnable runs while
another thread has the Log lock, a deadlock can occur. Instead, a normal
android.Runnable will be used in order to prevent the deadlock from
occuring.

Bug: 27552152
Change-Id: Ie41aac6d77db243daa048a9a8b0e2217b9c3ac5c