Add crash file information to android watchdog

Right now, the crash stacks up to a point are streamed through watchdog
after being read from a file.  On priveleged processes, the file can be
read directly and not truncated.  This is useful for more complete crash
collection information collection.

BUG=b/305603492
BUG=b/298274935
Test: ran on vm and observed log output.

Change-Id: Ia94e2aaf79d51075eb80a1efe5d9b5df26d21812