meta-google: Set default timezone as PDT

This is the prod configuration.

Change-Id: I04c33362cf874637caa528779c57bcacfca50201
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/meta-google/recipes-extended/timezone/tzdata.bbappend b/meta-google/recipes-extended/timezone/tzdata.bbappend
new file mode 100644
index 0000000..ec0c3c9
--- /dev/null
+++ b/meta-google/recipes-extended/timezone/tzdata.bbappend
@@ -0,0 +1 @@
+DEFAULT_TIMEZONE:gbmc = "PST8PDT"