Remove dumping raft logs

Raft has been replaced by logpersistd per b/28633932.
Remove code to handle raft logs.

BUG: 28633932
Test: adb shell /data/nativetest64/dumpstate_test/dumpstate_test
Test: adb bugreport ~/br.zip
Change-Id: I5380ed1367c4dc39a1531a9b3c61a3965fe56981