update OAT.xml.

Signed-off-by: Nduangavin123 <duanxichao@huawei.com>

OAT.xml

@@ -62,7 +62,7 @@
                 <!--filteritem type="filename" name="*.uvwxyz" desc="Describe the reason for filtering scan results"/-->
                 <!--filteritem type="filepath" name="abcdefg/.*.uvwxyz" desc="Describe the reason for filtering scan results"/-->
                 <!--filteritem type="filepath" name="projectroot/[a-zA-Z0-9]{20,}.sh" desc="Temp files"/-->
-				<filteritem type="filname" name="*.jpg|*.png|*.gif" desc="already checked"/>
+				<filteritem type="filname" name="*.jpg|*.png|*.gif|*.pdf" desc="already checked"/>
             </filefilter>
 
         </filefilterlist>