releasetools: ota_from_target_files: add FullOTA_PostValidate

Change-Id: I152412049f90fd546d4516cc064238c3192be553

tools/releasetools/common.py

@@ -3176,6 +3176,11 @@ class DeviceSpecificParams(object):
     used to install the image for the device's baseband processor."""
     return self._DoCall("FullOTA_InstallEnd")
 
+  def FullOTA_PostValidate(self):
+    """Called after installing and validating /system; typically this is
+    used to resize the system partition after a block based installation."""
+    return self._DoCall("FullOTA_PostValidate")
+
   def IncrementalOTA_Assertions(self):
     """Called after emitting the block of assertions at the top of an
     incremental OTA package.  Implementations can add whatever