fbpacktool: Update to current version

Source:
https://source.android.com/static/docs/core/architecture/bootloader/tools/pixel/fw_unpack/*.py

Modified to comment out
'from google3.third_party.devsite.androidsource.en.docs.core.architecture.bootloader.tools.pixel.fw_unpack'
from imports.

Change-Id: Ie81b52969633435ff303a89309868509436392ab

fbpacktool/packedstruct.py

@@ -12,50 +12,52 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+import collections
 import struct
 
 
 class PackedStruct(object):
-    """Class representing a C style packed structure
+  """Class representing a C style packed structure.
 
-    Derived classes need to provide a dictionary with key will be the attributes and the values are
-    the format characters for each field. e.g.
+  Derived classes need to provide a dictionary where the keys are the attributes
+  and the values are the format characters for each field. e.g.
 
-    class Foo(PackedStruct):
-        _FIELDS = {
-            x: 'I',
-            name: '64s',
-        }
+  class Foo(PackedStruct):
+      _FIELDS = {
+          x: 'I',
+          name: '64s',
+      }
 
-    In this case Foo.x will represent an "unsigned int" C value, while Foo.name will be a "char[64]"
-    C value
+  In this case Foo.x will represent an "unsigned int" C value, while Foo.name
+  will be a "char[64]" C value.
+  """
+  _FIELDS: collections.OrderedDict
 
-    """
+  def __init__(self, *args, **kwargs):
+    self._fmt = '<' + ''.join(fmt for fmt in self._FIELDS.values())
+    for name in self._FIELDS:
+      setattr(self, name, None)
 
-    def __init__(self, *args, **kwargs):
-        self._fmt = '<' + ''.join(fmt for fmt in self._FIELDS.values())
-        for name in self._FIELDS:
-            setattr(self, name, None)
+    for name, val in zip(self._FIELDS.keys(), args):
+      setattr(self, name, val)
+    for name, val in kwargs.items():
+      setattr(self, name, val)
 
-        for name, val in zip(self._FIELDS.keys(), args):
-            setattr(self, name, val)
-        for name, val in kwargs.items():
-            setattr(self, name, val)
+  def __repr__(self):
+    return '{} {{\n'.format(self.__class__.__name__) + ',\n'.join(
+        '    {!r}: {!r}'.format(k, getattr(self, k))
+        for k in self._FIELDS) + '\n}'
 
-    def __repr__(self):
-        return '{} {{\n'.format(self.__class__.__name__) + ',\n'.join(
-            '    {!r}: {!r}'.format(k, getattr(self, k)) for k in self._FIELDS) + '\n}'
+  def __str__(self):
+    return struct.pack(self._fmt, *(getattr(self, x) for x in self._FIELDS))
 
-    def __str__(self):
-        return struct.pack(self._fmt, *(getattr(self, x) for x in self._FIELDS))
+  def __bytes__(self):
+    return struct.pack(self._fmt, *(getattr(self, x) for x in self._FIELDS))
 
-    def __bytes__(self):
-        return struct.pack(self._fmt, *(getattr(self, x) for x in self._FIELDS))
+  def __len__(self):
+    return struct.calcsize(self._fmt)
 
-    def __len__(self):
-        return struct.calcsize(self._fmt)
-
-    @classmethod
-    def from_bytes(cls, data):
-        fmt_str = '<' + ''.join(fmt for fmt in cls._FIELDS.values())
-        return cls(*struct.unpack(fmt_str, data))
+  @classmethod
+  def from_bytes(cls, data):
+    fmt_str = '<' + ''.join(fmt for fmt in cls._FIELDS.values())
+    return cls(*struct.unpack(fmt_str, data))