[Autotest][PY3] Update client/bin/result_tools for python3 compatibility

Adjusting the imports in result_tools to support python3.
These ones are a bit weird, result_tools can be run **in** autotest, or as a
standalone lib. Because of this we need to adjust imports to be non-relative
for autotest support, but also leave the relative (under the except) for
standalone support

BUG=chromium:990593
TEST=dummy_pass in python 2 and 3. applicable unittests

Change-Id: I38d425c1d0a19aa7f7981e996b7b03a651699e72
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2570083
Reviewed-by: Gregory Nisbet <gregorynisbet@google.com>
Commit-Queue: Derek Beckett <dbeckett@chromium.org>
Tested-by: Derek Beckett <dbeckett@chromium.org>
diff --git a/client/bin/result_tools/dedupe_file_throttler.py b/client/bin/result_tools/dedupe_file_throttler.py
index f682b56..48b740e 100644
--- a/client/bin/result_tools/dedupe_file_throttler.py
+++ b/client/bin/result_tools/dedupe_file_throttler.py
@@ -11,9 +11,15 @@
 import os
 import re
 
-import result_info_lib
-import throttler_lib
-import utils_lib
+try:
+    from autotest_lib.client.bin.result_tools import result_info_lib
+
+    from autotest_lib.client.bin.result_tools import throttler_lib
+    from autotest_lib.client.bin.result_tools import utils_lib
+except ImportError:
+    import result_info_lib
+    import throttler_lib
+    import utils_lib
 
 
 # Number of files to keep for the oldest files.
diff --git a/client/bin/result_tools/delete_file_throttler.py b/client/bin/result_tools/delete_file_throttler.py
index cd26c0d..69bc10d 100644
--- a/client/bin/result_tools/delete_file_throttler.py
+++ b/client/bin/result_tools/delete_file_throttler.py
@@ -6,8 +6,12 @@
 
 import os
 
-import throttler_lib
-import utils_lib
+try:
+    from autotest_lib.client.bin.result_tools import throttler_lib
+    from autotest_lib.client.bin.result_tools import utils_lib
+except ImportError:
+    import throttler_lib
+    import utils_lib
 
 
 # Default threshold of file size in KB for a file to be qualified for deletion.
diff --git a/client/bin/result_tools/result_info.py b/client/bin/result_tools/result_info.py
index f1685e0..312d3b6 100644
--- a/client/bin/result_tools/result_info.py
+++ b/client/bin/result_tools/result_info.py
@@ -10,8 +10,12 @@
 import json
 import os
 
-import result_info_lib
-import utils_lib
+try:
+    from autotest_lib.client.bin.result_tools import result_info_lib
+    from autotest_lib.client.bin.result_tools import utils_lib
+except ImportError:
+    import result_info_lib
+    import utils_lib
 
 
 class ResultInfoError(Exception):
diff --git a/client/bin/result_tools/shrink_file_throttler.py b/client/bin/result_tools/shrink_file_throttler.py
index 887e2bf..e610845 100644
--- a/client/bin/result_tools/shrink_file_throttler.py
+++ b/client/bin/result_tools/shrink_file_throttler.py
@@ -5,8 +5,12 @@
 import os
 import re
 
-import throttler_lib
-import utils_lib
+try:
+    from autotest_lib.client.bin.result_tools import throttler_lib
+    from autotest_lib.client.bin.result_tools import utils_lib
+except ImportError:
+    import throttler_lib
+    import utils_lib
 
 
 # File extensions that can be safely shrunk.
diff --git a/client/bin/result_tools/throttler_lib.py b/client/bin/result_tools/throttler_lib.py
index 2efccae..55ac60b 100644
--- a/client/bin/result_tools/throttler_lib.py
+++ b/client/bin/result_tools/throttler_lib.py
@@ -7,7 +7,10 @@
 import os
 import re
 
-import utils_lib
+try:
+    from autotest_lib.client.bin.result_tools import utils_lib
+except ImportError:
+    import utils_lib
 
 
 # A list of file names that should not be throttled, that is, not modified by
diff --git a/client/bin/result_tools/utils.py b/client/bin/result_tools/utils.py
index ce00408..c40af66 100755
--- a/client/bin/result_tools/utils.py
+++ b/client/bin/result_tools/utils.py
@@ -38,18 +38,27 @@
 import logging
 import os
 import random
+from six.moves import range
 import sys
 import time
 import traceback
 
-import dedupe_file_throttler
-import delete_file_throttler
-import result_info
-import shrink_file_throttler
-from six.moves import range
-import throttler_lib
-import utils_lib
-import zip_file_throttler
+try:
+    from autotest_lib.client.bin.result_tools import dedupe_file_throttler
+    from autotest_lib.client.bin.result_tools import delete_file_throttler
+    from autotest_lib.client.bin.result_tools import result_info
+    from autotest_lib.client.bin.result_tools import shrink_file_throttler
+    from autotest_lib.client.bin.result_tools import throttler_lib
+    from autotest_lib.client.bin.result_tools import utils_lib
+    from autotest_lib.client.bin.result_tools import zip_file_throttler
+except ImportError:
+    import dedupe_file_throttler
+    import delete_file_throttler
+    import result_info
+    import shrink_file_throttler
+    import throttler_lib
+    import utils_lib
+    import zip_file_throttler
 
 
 # Do NOT import autotest_lib modules here. This module can be executed without
diff --git a/client/bin/result_tools/zip_file_throttler.py b/client/bin/result_tools/zip_file_throttler.py
index 0f1d4fe..aa1b586 100644
--- a/client/bin/result_tools/zip_file_throttler.py
+++ b/client/bin/result_tools/zip_file_throttler.py
@@ -9,8 +9,12 @@
 import os
 import tarfile
 
-import throttler_lib
-import utils_lib
+try:
+    from autotest_lib.client.bin.result_tools import throttler_lib
+    from autotest_lib.client.bin.result_tools import utils_lib
+except ImportError:
+    import throttler_lib
+    import utils_lib
 
 
 # File with extensions that can not be zipped or compression won't reduce file