scripts: update open calls to use explicit encoding

BUG=b:187789896
TEST=`cros lint` is clean here

Change-Id: Ia54475869c17292505537334362cd4cff6438b14
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/4290041
Commit-Queue: Cindy Lin <xcl@google.com>
Reviewed-by: Cindy Lin <xcl@google.com>
Tested-by: Mike Frysinger <vapier@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_generate_android_breakpad_symbols.py b/scripts/cros_generate_android_breakpad_symbols.py
index a4a2924..aca3727 100644
--- a/scripts/cros_generate_android_breakpad_symbols.py
+++ b/scripts/cros_generate_android_breakpad_symbols.py
@@ -140,7 +140,7 @@
     # packed binaries.).
     unpack_cmd = [RELOCATION_PACKER_BIN, "-u", elf_file]
     unpack_result = cros_build_lib.run(
-        unpack_cmd, stdout=True, check=False, encoding="utf8"
+        unpack_cmd, stdout=True, check=False, encoding="utf-8"
     )
 
     # If we unpacked, extract the offset, and remember it.