Fix _build_date() crash on non-standard locale date strings (#2513)

Some Android devices return locale-dependent strings in ro.build.date
(e.g. '2017年 11月 14日 星期二 09:55:07 CST' for Chinese locale) that
dateutil.parser.parse() cannot handle, causing wait_for_device() to
crash with a ParserError.

Fix: prefer ro.build.date.utc (integer epoch timestamp) which is
locale-independent and available on all Android devices. Fall back
to ro.build.date with error handling if the UTC property is missing.

Author: coder999999999

pwnlib/adb/adb.py

@@ -1275,8 +1275,20 @@ def __hash__(self, other):
 
 def _build_date():
     """Returns the build date in the form YYYY-MM-DD as a string"""
+    # Prefer ro.build.date.utc (integer epoch) as ro.build.date is
+    # locale-dependent and may contain non-ASCII characters that
+    # dateutil cannot parse (e.g. Chinese locale dates).  See #2513.
+    utc = getprop('ro.build.date.utc')
+    if utc and utc.strip().isdigit():
+        import datetime
+        as_datetime = datetime.datetime.fromtimestamp(int(utc.strip()), tz=datetime.timezone.utc)
+        return as_datetime.strftime('%Y-%b-%d')
+
     as_string = getprop('ro.build.date')
-    as_datetime =  dateutil.parser.parse(as_string)
+    try:
+        as_datetime = dateutil.parser.parse(as_string)
+    except (ValueError, OverflowError):
+        return as_string
     return as_datetime.strftime('%Y-%b-%d')
 
 def find_ndk_project_root(source):